Devices and methods for coronary sinus pressure relief

ABSTRACT

A method and devices for relieving pressure in the left atrium of a patient&#39;s heart is disclosed. The method includes using an ablative catheter in a minimally invasive procedure to prepare an opening from the coronary sinus into a left atrium of the patient&#39;s heart. Once the opening is prepared, the opening may be enlarged by a technique such as expanding a balloon within the opening. A stent is then placed within the coronary sinus of the patient, with a transverse portion expanding within the opening, allowing blood to flow from the left atrium to the coronary sinus and then to the right atrium. Pressure within the left atrium is thus relieved.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/152,094, filed Jan. 10, 2014, which is a continuation of U.S. patentapplication Ser. No. 13/167,502, filed Jun. 23, 2011, now abandoned,which claim the benefit of U.S. Provisional Application No. 61/449,566,filed Mar. 4, 2011, each of which is herein incorporated by reference inits entirety.

The present application incorporates by reference the followingapplications: U.S. application Ser. No. 12/954,468, filed Nov. 24, 2010;U.S. Provisional Application No. 61/240,085 filed Sep. 4, 2009; U.S.application Ser. No. 12/719,843, filed Mar. 8, 2010; U.S. ProvisionalApplication No. 61/299,559, filed Jan. 29, 201.0; U.S. application Ser.No. 12/447,617, filed Apr. 28, 2009; international ApplicationPCT/AU2007/001704, filed Nov. 7, 2007; and Australian Patent ApplicationNo. AU 2006906202 filed Nov. 7, 2006.

FIELD

The present disclosure relates generally to devices and methods fortreating heart failure. In particular, the disclosure relates tointeratrial pressure vents, shunts and the like, which reduce elevatedpressure on one side of the heart thus mitigating the symptoms thatresult, as well as placement devices, systems, and methods therefore.

BACKGROUND

Heart failure is a common and potentially lethal condition affectinghumans, with sub-optimal clinical outcomes often resulting in symptoms,morbidity and/or mortality, despite maximal medical treatment. Inparticular, “diastolic heart failure” refers to the clinical syndrome ofheart failure occurring in the context of preserved left ventricularsystolic function (ejection fraction) and in the absence of majorvalvular disease. This condition is characterized by a stiff leftventricle with decreased compliance and impaired relaxation, which leadsto increased end-diastolic pressure. Approximately one third of patientswith heart failure have diastolic heart failure and there are very few,if any, proven effective treatments.

Symptoms of diastolic heart failure are due, at least in a large part,to an elevation in pressure in the left atrium. In addition to diastolicheart failure, a number of other medical conditions, including systolicdysfunction of the left ventricle and valve disease, can lead toelevated pressures in the left atrium. Increased left atrial pressureoften causes acute or chronic breathlessness amongst other problems. Inaddition, a variety of heart conditions can lead to “right heartfailure”, which can result in enlargement of the liver (hepatomegaly),fluid accumulation in the abdomen (ascites) and/or swelling of the lowerlimbs.

Frequently, patients with diastolic heart failure experiencebreathlessness due, in part, to elevated pulmonary venous pressure.These patients often feel worse when supine than when sitting orstanding, implying that small changes in pulmonary venous pressure havea pronounced effect on symptoms.

In the past, strategies have been described for the relief of highpressure in the right atrium, such as the creation of hole(s) in thenative or surgically created septum between the left and right atria.These have been designed for the rare conditions of pulmonaryhypertension or cavopulmonary connections for certain complex congenitalheart diseases.

The functioning of the heart and the opening and closing of heart valvesoccur primarily as a result of pressure differences. For example, theopening and closing of the mitral valve between the left atrium and theleft ventricle occurs as a result of the pressure differences betweenthe left atrium and the left ventricle. During ventricular diastole(ventricular filling), when ventricles are relaxed, the venous return ofblood from the pulmonary veins into the left atrium causes the pressurein the atrium to exceed that in the ventricle. As a result, the mitralvalve opens, allowing blood to enter the ventricle. As the ventriclecontracts during ventricular systole (ventricular emptying), theintraventricular pressure rises above the pressure in the atrium andpushes the mitral valve shut. Blood then is pumped from the ventriclesto the arteries.

The heart has four valves to ensure that blood does not flow in thewrong direction during the cardiac cycle; that is, to ensure that theblood does not back flow from the ventricles into the correspondingatria, or back flow from the arteries into the corresponding ventricles.The valve between the left atrium and the left ventricle is the mitralvalve. The valve between the right atrium and the right ventricle is thetricuspid valve. The pulmonary valve is at the opening of the pulmonaryartery. The aortic valve is at the opening of the aorta.

Blood flowing back from the left ventricle into the left atrium, orsystolic dysfunction of the left ventricle and valve disease, asmentioned in the background, may cause high atrial pressure and reducethe flow of blood into the left atrium from the lungs. As blood backs upinto the pulmonary system, fluid leaks into the lungs and causespulmonary edema. Blood volume going to the atrium reduces volume ofblood going forward into the aorta causing low cardiac output. Excessblood in the atrium over-fills the ventricle during each cardiac cycleand causes volume overload in the left ventricle.

Heart failure with such symptoms is a common and potentially lethalcondition affecting humans, with sub-optimal clinical outcomes oftenresulting in symptoms, morbidity and/or mortality, despite maximalmedical treatment. In particular, “diastolic heart failure” refers tothe clinical syndrome of heart failure occurring in the context ofpreserved left ventricular systolic function (ejection fraction) and inthe absence of major valvular disease. This condition is characterizedby a stiff left ventricle with decreased compliance and impairedrelaxation, which leads to increased end-diastolic pressure.Approximately one third of patients with heart failure have diastolicheart failure and there are very few, if any, proven effectivetreatments.

Symptoms of diastolic heart failure are due, at least in a large part,to an elevation in pressure in the left atrium. In addition to diastolicheart failure, a number of other medical conditions, including systolicdysfunction of the left ventricle and valve disease, can lead toelevated pressures in the left atrium. Increased left atrial pressureoften causes acute or chronic breathlessness amongst other problems. Inaddition, a variety of heart conditions can lead to “right heartfailure”, which can result in enlargement of the liver (hepatomegaly),fluid accumulation in the abdomen (ascites) and/or swelling of the lowerlimbs.

Frequently, patients with diastolic heart failure experiencebreathlessness due, in part, to elevated pulmonary venous pressure.These patients often feel worse when supine than when sitting orstanding, implying that small changes in pulmonary venous pressure havea pronounced effect on symptoms.

In the past, strategies have been described for the relief of highpressure in the right atrium, such as the creation of hole(s) in thenative or surgically created septum between the left and right atria.These have been designed for the rare conditions of pulmonaryhypertension or cavopulmonary connections for certain complex congenitalheart diseases. Accordingly, there still exists a need for devices andmethods to treat heart failure, particularly diastolic and/or systolicfailure of the left ventricle and its consequences.

Furthermore, there also still exists a need for devices to relieve highpressure in the left atrium and which will prevent or minimize thechance of the passage of thrombi and the resulting risk of systemicemboli.

SUMMARY OF THE DISCLOSURE

One embodiment is a stent for use in a patient. The stent includes aplurality of struts and a plurality of intersections joining the strutsto form a stent having a longer cylindrical portion and a shortercylindrical portion adjacent the longer cylindrical portion andextending beyond the longer cylindrical portion in a directionperpendicular to an axis of the longer cylindrical portion, wherein thelonger cylindrical portion is adapted to fit into and bear against acoronary sinus and wherein the stent is adapted to form an opening fromthe coronary sinus to a left atrium of the patient.

Another embodiment is a stent for use in a patient. The stent includes alonger, radially-expanding portion adapted for placement in a coronarysinus of the patient and a shorter portion adjacent and joined to thelonger, radially-expanding portion, the shorter portion extending beyondthe longer, radially-expanding portion in a direction perpendicular toan axis of the longer radially-expanding portion, the shorter portionadapted for placement within a left atrium of the patient, wherein thelonger, radially-expanding portion is adapted to hear against a wall ofthe coronary sinus and wherein the shorter portion is adapted to form anopening between the left atrium and the coronary sinus of the patient.

Another embodiment is a method for relieving intracardial pressure. Themethod includes steps of providing an opening between a left atrium of aheart and a coronary sinus and allowing blood to flow from the leftatrium into the coronary sinus.

Another embodiment is a method for relieving intracardial pressure. Themethod includes steps of furnishing a stent suitable for implantationinto a coronary sinus of a patient, the stent suitable for extendingfrom the coronary sinus to within a left atrium of the patient and formaintaining communication between the left atrium and the coronarysinus, preparing an opening in the left atrium using at least oneinstrument in the coronary sinus, maneuvering the stent into thecoronary sinus to a position near the opening, and deploying a portionof the stent into the opening, wherein the stent maintains communicationbetween the left atrium and the coronary sinus.

Another embodiment is also a method for relieving intracardial pressure.The method includes steps of furnishing a stent suitable forimplantation into coronary sinus of a patient, the stent suitable forextending from the coronary sinus to within a left atrium of the patientand maintaining for communication between the left atrium and thecoronary sinus, preparing an opening in a wall between the left atriumand the coronary sinus, maneuvering the stent to a position near theopening, and deploying the stent into the opening, wherein the stentmaintains communication between the left atrium and the coronary sinus.

These and other needs are met by providing an opening between the leftatrium and the coronary sinus to provide communication between the leftatrium and the coronary sinus, enabling the relief of pressure in theleft atrium. Other needs are met by providing within the opening aventing device, a prosthesis, within the opening between the left atriumand the coronary sinus.

Yet other needs are met by providing within the opening a ventingdevice, a prosthesis, such as an interatrial pressure vent, which insome embodiments comprises a controlled opening or an extended tubularopening, between the left atrium and right atrium that allows an amountof blood to vent from the left heart to the right heart, therebyreducing left atrial pressure and the symptoms associated with diastolicheart failure.

Several unique intracardiac pressure vents, placement catheters, methodsof placement and methods of treating heart failure are presented. Theintracardiac pressure vents or prostheses presented allow sufficientflow from the left atrium to the right atrium to relieve elevated leftatrial pressure and resulting patient symptoms but also limit the amountof flow from the right atrium to the left atrium to minimize thepotential for thrombi or other embolic material from entering thearterial circulation.

In addition, the intracardiac pressure vents or prostheses presentedsolve the problem of controlling flow in one direction but minimizingflow in another direction with very low changes in pressure across thedevice.

Also, the intracardiac pressure vents presented solve the problem ofreducing calcium deposition, protein deposition and thrombi formation ina low pressure environment.

Furthermore, the intracardiac pressure vents presented solve the problemof damage to the interatrial septum as well as the rest of the leftatrium from excessive pressure against the wall which can cause injuryto the tissue and possibly adverse reaction by the patient orcompromised function to the interatrial pressure vent.

In addition, atrial arrhythmias are frequently seen in patients withheart failure and may, in part, be caused by chronically elevated leftatrial pressure. Therefore, relief of elevated left atrial pressure maylead to reduction of atrial fibrillation.

The present disclosure provides prostheses, that is, interatrialpressure vents, along with placement catheters, methods for placing adevice in the interatrial septum within the heart of a patient andmethods for treatment of the symptoms of heart failure, particularlydiastolic heart failure.

In embodiments, the interatrial pressure vent or prosthesis comprises abody assembly and a flow control element; the body assembly comprises aflexible, substantially open mesh adapted for use in a patient. The flowcontrol element attaches to at least one point of the body assembly andthe flow control element provides greater resistance to flow in onedirection than it does in another direction.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element; the body assembly comprises a flexible,substantially open mesh adapted for use in a patient. The flow controlelement attaches to at least one point of the body assembly and is atleast partially open to flow when there is no pressure differentialacross the flow control element.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element; the body assembly comprises a core segmentand at least one flange segment; the flange segment is integral with, orattached to at least one point adjacent to, an end of the core segment;the flange segment extends radially outward from the center longitudinalaxis of the core segment. The flow control element attaches to at leastone point along the core segment and the flow control element providesgreater resistance to flow in one direction than in the oppositedirection.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element; the body assembly comprises a substantiallycylindrical core segment and at least one flange segment; the flangesegment is integral with, or attached at least to one point adjacent to,an end of the core segment; the flange segment extending radiallyoutward from the center longitudinal axis of the core segment. The flowcontrol element attaches to at least one point along the core segmentand the flow control element provides greater resistance to flow in onedirection than another direction.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element. The body assembly comprises a substantiallycylindrical core segment and at least one flange segment integral with,or attached to at least one end of, the core segment; the flange segmentextending radially outward from the axis of the core segment. The flowcontrol element attaches to at least one point along the core segmentand the flow control element is at least partially open to flow whenthere is no pressure differential across the flow control element.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element. The body assembly comprises a substantiallycylindrical core segment and at least one flange segment integral with,or attached to at least one end of, the core segment and extending awayfrom the axis of the core segment. The flow control element attaches toat least one point along the flange assembly and provides greaterresistance to flow in one direction than the other direction.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element. The body assembly comprises a substantiallycylindrical core segment and at least one flange segment integral with,or attached to at least one end of, the core segment and extending awayfrom the axis of the core segment. The flow control element attaches toat least one point along the flange assembly and is at least partiallyopen to flow when there is no pressure differential across the flowcontrol element.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element. The body assembly comprises a substantiallycylindrical core segment and at least one flange segment integral with,or attached to at least one end of, the core segment and extending awayfrom the axis of the core segment. The flow control element extends atleast partly onto the flange assembly and creates a sealable contact tothe atrial septum and provides greater resistance to flow in onedirection than the other direction.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element. The body assembly comprises a substantiallycylindrical core segment and at least one flange segment integral with,or attached to, at least one end of the core segment and extends awayfrom the axis of the core segment. The flow control element attaches tothe flange assembly and creates a sealable connection to the atrialseptum and is at least partially open to flow when there is no pressuredifferential across the flow control element.

In embodiments, the interatrial pressure vent comprises a body assemblywith a first end and a second end and a flow control element; the bodyassembly comprises a core segment including at least one flange segmentintegral with, or attached to, at least one point adjacent to the firstend of the core segment and at least one other flange segment integralwith, or attached to, at least one point adjacent to the second end ofthe core segment; the flange segments extending radially outward fromthe center longitudinal axis of the core segment and the flange segmentsoriented so they do not oppose each other when deployed. The flowcontrol element attaches to at least one point along the core segmentand the flow control element provides greater resistance to flow in onedirection than it does in another direction.

In embodiments, the interatrial pressure vent comprises a body assemblywith a first end and a second end and a flow control element; the bodyassembly comprises a core segment including at least one flange segmentintegral with, or attached to, at least one point adjacent to the firstend of the core segment and at least one other flange segment integralwith, or attached to, at least one point adjacent to the second end ofthe core segment; the flange segments extending radially outward fromthe center longitudinal axis of the core segment and the flange segmentsoriented so they do not oppose each other when deployed. The flowcontrol element attaches to at least one point along the core segmentand the flow control element is at least partially open to flow whenthere is no pressure differential across the flow control element.

In embodiments, the interatrial pressure vent comprises a body assemblywith a first end and a second end and a flow control element comprisedof at least one leaflet; the body assembly comprises a substantiallycylindrical core segment and a number of flange segments integral with,or attached to, at least one point on each side of the body segment andextending radially outward from the center longitudinal axis of the coresegment; the number of flange segments on either side of the coresegment being a whole multiple of the number of leaflets.

In embodiments, the interatrial pressure vent comprises a body assemblywith a first end and a second end and a flow control element comprisedof at least one leaflet; the body assembly comprises a substantiallycylindrical core segment and a number of flange segments integral with,or attached to, at least one point on each side of the body segment andextending radially outward from the center longitudinal axis of the coresegment; the number of flange segments being a whole multiple of thenumber of leaflets. The flow control element attaches to at least onepoint of the body assembly and the flow control element provides greaterresistance to flow in one direction than another direction.

In embodiments, the interatrial pressure vent comprises a body assemblywith a first end and a second end and a flow control element comprisedof at least one leaflet; the body assembly comprises a substantiallycylindrical core segment and a number of flange segments integral with,or attached to, at least one point on each side of the body segment andextending radially outward from the center longitudinal axis of the coresegment; the number of flange segments being some multiple of the numberof leaflets. The flow control element attaches to at least one point ofthe body assembly and is at least partially open to flow when there isno pressure differential across the flow control element.

In embodiments, an implant system comprises an interatrial pressure ventand placement catheter for treating heart failure. The implant system iscomprised of a body assembly and a flow control element. The bodyassembly is comprised of a substantially cylindrical core segment and atleast one flange segment integral with, or attached to, at least one endof the core segment and extending radially away from the core segment.The flow control element is attached to at least one point along thecore segment and provides greater resistance to flow in one directionthan the other direction. The placement catheter is comprised of aninner shaft and an outer shaft. The inner shaft comprises an elongatetube and a handle component. The inner shaft also contains at least onelumen that extends along at least part of the length of the inner shaft.The outer shaft comprises an elongate hollow tube or sheath and adifferent handle component that slideably interfaces with the firsthandle component.

In embodiments, an implant system comprises and interatrial pressurevent and placement catheter for treating heart failure. The implantsystem is comprised of a body assembly and a flow control element. Thebody assembly is comprised of a substantially cylindrical core segmentand at least one flange segment integral with, or attached to, at leastone end of the body assembly and extending radially away from the bodysegment. The flow control element is attached to at least one pointalong a flange and provides greater resistance to flow in one directionthan the other direction. The placement catheter is comprised of aninner shaft and an outer shaft. The inner shaft comprises an elongatetube and a handle component. The inner shaft also contains at least onelumen that extends along at least part of the length of the inner shaft.The outer shaft comprises an elongate hollow tube (or sheath) and adifferent handle component that slideably interfaces with the firsthandle component.

In embodiments, an implant system comprises and interatrial pressurevent and placement catheter for treating heart failure. The implantsystem is comprised of a body assembly and a flow control element. Thebody assembly is comprised of a substantially cylindrical core segmentand at least one flange segment integral with, or attached to, at leastone end of the body assembly and extending radially away from the bodysegment. The flow control element is attached to at least one pointalong a flange and provides greater resistance to flow in one directionthan the other direction. The placement catheter is comprised of aninner shaft and an outer shaft. The inner shaft comprises an elongatetube with at least one flange or circumferential groove formed in theouter diameter and a handle component. The inner shaft also contains atleast one lumen that extends along at least part of the length of theinner shaft. The outer shaft comprises art elongate hollow tube (orsheath) and a different handle component that slideably interfaces withthe first handle component.

In other embodiments, an embodiment comprises a device for treating aheart condition in a patient comprising a body element having a coresegment defining a passage, a first annular flange comprising aplurality of flange segments, and a second annular flange comprising aplurality of flange segments. In embodiments, at least a portion of oneof the flange segments is either more or less flexible than theremaining portion of the flange segment or other portions of the bodyelement, including but not limited to the cylindrical core segment. Inone embodiment, the first annular flange is less flexible than thesecond flange, which is more flexible than the first annular flange.

In other embodiments, the device comprises a third or intermediateannular flange for better adherence to the septal wall.

In other embodiments, the device comprises a flow control elementconfigured to aim the flow of blood in a desired direction. In otherembodiments, the device is configured to be more easily retrieved duringdeployment. Such embodiments can include among other elements a at leastone extended flange segment in one of the annular flanges that is ableto be retained within a placement catheter when the other portions ofthe device are deployed.

In embodiments, the method of placing the interatrial pressure vent intoposition may comprise a sequence of steps to locate and gain access to avascular channel leading to the heart, placing an introducer cathetervia this channel into one of the atriums of the heart, locating theinteratrial septum between the left and right atriums, creating anopening in the interatrial septum, advancing a placement cathetercontaining an interatrial pressure vent into one of the atriums and thenthrough the opening created in the interatrial septum between the rightand left atriums, and then controllably deploying the interatrialpressure vent so it is securably connected to the interatrial septum.

Deployment of the interatrial pressure vent preferably occurs in aseries of steps comprising first advancing the placement catheterthrough the septal opening, second deploying a first flange, thirdretracting the placement catheter to position the first flange againstthe septal wall, and fourth deploying a second flange on the other sideof the septal wall from the first flange.

In embodiments where the device disclosed herein is implanted into theatrial septum, the introducer catheter may be placed through theinferior vena cava via a femoral vein to the right atrium.

Other pathways are available including placing the introducer catheterthrough the superior vena cava via a jugular vein; through the aorta,via a femoral artery, past the aortic valve and into the left atrium;through the aorta, via a brachial artery, past the aortic valve and intothe left atrium; through the superior vena cava via a basilica vein;through the superior vena cava via a cephalic vein; intraoperatively,through an opening created in the right atrium either for this reason orduring a procedure performed for some other purpose; intraoperativelythrough an opening created in the left atrium either for this reason orduring a procedure performed for some other reason; or via a guidewirethat is positioned through the interatrial septum and located in thepulmonary artery.

Regarding the placement catheter, in some embodiments the placementcatheter is designed to function as the introducer catheter and theplacement catheter, eliminating the need for a catheter exchange. Whilein other embodiments, the introducer catheter, the placement catheter,or both are constructed to be exchanged over only part of their lengthto avoid the necessity of handling a guidewire that is at least twice aslong as the catheter. Still in other embodiments, the introducercatheter or the placement catheter, or both has a pre-shaped curve toenable orientation of the placement catheter substantially orthogonal tothe septal wall. The catheter may be curved between 30° and 45° awayfrom the catheter axis at a point between 5 and 1.5 centimeters awayfrom the distal end of the placement catheter.

In embodiments where the inventive device is to be placed in the atrialseptum, an opening in the septum can be performed using the introducercatheter in a separate procedure from the interatrial pressure ventplacement procedure. Access through the opening can be maintained via awireguide positioned in the right atrium or the pulmonary artery. Theopening can be formed using the placement catheter via a distal tipsegment that is part of the placement catheter.

The opening may be predilated using a balloon or other dilating deviceeither as part of the procedure described or as a separate procedure.

In another aspect, the opening is formed and dilated as part of asingle, unified procedure with the interatrial pressure vent placementprocedure. This may be accomplished by integrating a balloon or otherdilating component as part of the placement catheter and dilating theopening as part of placing the interatrial pressure vent. For example,this could be accomplished using a balloon that can be folded to achievea small loaded profile and will have a suitable pressure capacity andsuitable durability to dilate the septum opening and the interatrialpressure vent together.

The opening that is formed in the interatrial septum may be formed bypushing a catheter tip through the septum at the location of septumprimum. Because this septum is normally very thin, the distal tip may bepushed directly through without significant force.

In an alternate method, the opening in the interatrial septum can beformed with a cutting tool that is advanced through the introducercatheter or the placement catheter. The tool preferably comprises ablade and a shaft. The blade contains at least two surfaces and oneedge. The edge is sharpened and formed at an angle so that the bladeslices as it is advanced into and through the septum.

In yet another method, the opening in the interatrial septum can beformed with a cutting tool that is advanced through the introducercatheter or the placement catheter. The tool preferably comprises ablade and a shaft. The blade contains at least two surfaces and twoseparate edges that are sharpened at an angle so that the blade slicesas it is advanced into and through the septum and the septum is cutgenerally in an x shaped opening.

In yet another method, the opening in the interatrial septum can beformed with a punching tool that is advanced through the introducercatheter or the placement catheter. The punching tool preferablycomprises a cutting assembly and a shaft. The cutting assemblypreferably comprises a hollow, conical shape with a sharpened edge alongthe base circumference. The cutting assembly is connected at least toone point on the shaft and is generally oriented so the apex of the coneis pointed away from the shaft.

In one method, the cutting assembly can be operated by advancing theconical assembly through the interatrial septum and then pulling it backto form an opening that is generally circular. In another method, thecutting assembly can be operated by advancing the conical assemblythrough the interatrial septum and then rotating it as it is pulled packto create a circular cutting action against the interatrial septum.

In another embodiment, the cutting tool can be formed of at least onecutting member and one shaft. The cutting member is connected at leastto one point along the shaft and the other end of the cutting member isadjustably positioned so it can lie alongside the shaft or at some angleaway from the shaft. To place the cutting tool, the cutting member isplaced alongside the shaft and then advanced through the septum. Thenthe cutting member would be adjusted to a second position, radiallyfurther away from the shaft than the first position, and the shaft wouldbe positioned so the cutting member exerts lateral stress against theseptum. The cutting member could be designed to slice the septum in thismanner. In another method, the cutting tool could be rotated once theshaft and cutting member were repositioned so the slicing motion wouldcut a generally circular hole through the septum.

In embodiments, the cutting member is round wire. In another embodiment,the cutting member can be connected to one output of a power supply,capable of supplying a suitable signal to the cutting member, the otheroutput of which is connected to a ground plate placed against thepatient's skin. An appropriate electric potential can be placed betweenthe cutting member and ground plate to cause a concentrated currentdensity near the wire to aid in cutting through the septum tissue.

In another embodiment, the cutting member is a section of tubing slicedlengthwise and appropriately formed to create a cutting edge. Duringplacement, the cutting member is controllably positioned to lie againstthe shaft as the shaft is advanced through the placement catheter andthrough the opening created in the interatrial septum. Once positioned,the placement catheter is retracted and the shaft is positioned withinthe septum. Once positioned in this manner, the cutting member can becontrollably adjusted to a second position, radially further away fromthe shaft than the first position, and the shaft positioned so thecutting member exerts lateral stress against the septum.

In yet another method, an opening is created in the interatrial septumwhich is smaller than the diameter of the outer surface of the body ofthe interatrial pressure vent according to the present disclosure suchthat, when the interatrial pressure vent is initially deployed withinthe interatrial septum, there is some compression from the septumagainst the body of the interatrial pressure vent.

Referring now to the placement catheter used to position andcontrollably place the interatrial pressure vent; in one aspect, theplacement catheter consists of an inner member and an outer member.

In embodiments, the outer member is comprised of a tubing member and afirst handle component, the outer shaft is less than about 16 F indiameter and formed of a material suitably smooth and resilient in orderto restrain the stowed interatrial pressure vent and allow smoothstowing and deployment, such as PTFE, FEP, modified ETFE fluoropolymer(such as Tefzel®), PVDF, HDPE or other suitable materials.

In embodiments, the inner member is comprised of at least one tubingmember with an inner lumen through at least part of the tubing member,and a second handle component attached to the proximal end, with thesecond handle component slideably attached to the first handlecomponent.

In embodiments, the handle components are interconnected via aninclined, helical lever to enable advancement of the inner memberrelative to the outer member by rotating the outer shaft handle whileholding the inner shaft handle.

In embodiments, the handle components comprise a locking mechanism thatprevents the handle component from moving in relationship to each otherbeyond a certain predetermined length.

In embodiments, the handle components contain at least two lockingmechanisms that prevents the handle component from moving inrelationship to each other beyond two different predetermined length.

In embodiments, the inner member contains a stiffening element adjacentto the distal area.

In embodiments, a system for treating heart failure in a patientconsists of an interatrial pressure vent and placement device. Theinteratrial pressure vent comprises a body section and a flow controlelement. The body section comprises a core section and at least oneflange segment. The flange segment comprises a midsection adjacent tothe body and an end section that has a greater wall thickness than themidsection. The placement device comprises an inner shaft and an outershaft. The inner shaft comprises an outside diameter and an internallumen extending at least partly toward the proximal end from the distalend.

The outer shaft contains an outside diameter and an inside diameter. Theinner shaft contains a necked portion or circumferential groove along atleast part of its length of smaller diameter than at least a portion ofthe inner member distal to the necked portion; the space formed betweenthe outside of the necked portion and the inside of the outer shaftbeing sufficient to contain a folded or otherwise compressed interatrialpressure vent of the present disclosure and the space formed between theoutside of the non-necked portion and the inside of the outer shaftbeing insufficient to contain the interatrial pressure vent.

In embodiments, a system for treating heart failure in a patientconsists of an interatrial pressure vent and placement device. Theinteratrial pressure vent comprises a body section and a flow controlelement. The body section comprises a core section and at least oneflange segment. The flange segment comprises a midsection adjacent tothe body and an end section located radially further away than themidsection and with a larger dimension in the radial direction than themidsection. The placement device comprises an inner shaft and an outershaft. The inner shaft contains an outside diameter and an internallumen extending at least partly toward the proximal end from the distalend. The outer shaft contains an outside diameter and an insidediameter. The inner shaft contains a first necked portion orcircumferential groove comprising a length and a diameter; the diameterof the first necked portion of the inner shaft being smaller than atleast a portion of the inner member distal to the necked portion and theinner shaft also containing a second necked portion, proximal to thefirst necked portion and of a length sufficient for containing endsection of the flange segment and a diameter smaller than the firstnecked portion; the space formed between the outside of the first neckedportion and the inside of the outer shaft being sufficient to containthe folded or otherwise compressed interatrial pressure vent of thepresent disclosure except for the end section of the flange segment; thespace formed between the outside of the non-necked portion and theinside of the outer shaft being insufficient to contain the interatrialpressure vent and the space formed between the outside of the secondnecked portion and the inside of the outer shaft being sufficient tocontain the end section of the flange segment.

In another aspect, the inner member comprises a first necked portionalong at least part of its length of smaller diameter than at least aportion of the inner member distal to the first necked portion andsecond necked portion, along a second part of its length proximal to thefirst necked portion and smaller than the first necked portion. Thespace between the outside of the necked portion and the inside of theouter sheath.

Referring now to the body assembly of the interatrial pressure vent, inone aspect, the body comprises a core segment and at least one flangesegment. In embodiments, the body assembly comprises a core segment; afirst flange comprising at least one flange segment at one end of thecore segment; and a second flange comprising at least one flange segmentat the opposite end from the first flange of the core segment.

In embodiments, the body assembly comprises a core segment, comprising aself expanding mesh; a first flange, at one end of the core segment; anda second flange at the opposite end of the core segment from the firstflange.

In embodiments, the body assembly is comprised of a core segment,comprising a balloon expandable mesh; a first flange at one end of thecore segment; and a second flange at the opposite end of the coresegment from the first flange.

In embodiments, the body assembly is comprised of a core segment; afirst flange at one end of the core segment; and a second flange at theopposite end of the core segment from the first flange; each flangeoriented to extend substantially radially outward relative to the centeraxis the flange segment.

In embodiments, the body assembly is comprised of a core segment; afirst flange at one end of the core segment; and a second flange at theopposite end of the core segment from the first flange; each flangeoriented to extend substantially radially outward from the core segment;and at least one flange extending beyond 90° relative to the center axisof the core segment.

In embodiments, the body assembly is comprised of a core segment; afirst flange at one end of the core segment; and a second flange at theopposite end from the first flange of the core segment; each flangeoriented to extend substantially radially outward from the core segment;the first flange formed with a smaller radius of curvature than thesecond flange.

In embodiments the interatrial pressure vent comprises a flow controlelement biased to allow flow from one atrium of a patient to the otheratrium of the patient with lower resistance than in the reversedirection.

In embodiments the interatrial pressure vent comprises a flow controlelement biased that remains at least partially open when there is nopressure differential across the vent.

In embodiments, the interatrial pressure vent comprises an integralfilter to prevent embolic particles larger than about 2 mm from passingbeyond the filter in the direction of flow.

In other embodiments, the interatrial pressure vent comprises a tubularflow element which extends a distance beyond the core segment so as toprevent embolic particles from entering the left atrium.

In embodiments, the interatrial pressure vent comprises at least onemovable flap that responds to pressure changes between the right andleft atrium.

In embodiments, the body assembly may be constructed from preformed wirebraid. The wire braid may be formed from nitinol with amartensite/austenite transition temperature is below 37° C. so itremains in its superelastic, austenitic phase during use. The transitiontemperature is below about 25+/−5° C. The wire should have a diameter ofat least about 0.0035 (about 2 lbs of breaking strength at 200 ksitensile). The wire should have a very smooth surface to reducethrombogenicity or irritation response from the tissue. The surfacefinish may be 63 μin RA or better. This surface may be obtained eitherby mechanical polishing, by electropolishing or a combination. Inembodiments, the surface may be cleaned with detergents, acids and/orsolvents to remove residual oils or contamination and then controllablypassivated to insure minimal corrosion.

In embodiments, the body assembly may be formed from grade 1 titanium.In embodiments, the body may be formed of grade 6 titanium. Inembodiments, the body may be formed of grade 9 titanium. In embodiments,the body may be formed of 316L, stainless steel. In embodiments, thebody may be formed of 416L stainless steel. In embodiments, the body maybe formed of nitinol or cobalt-chromium-nickel alloy (such as Elgiloy®).In embodiments, the body is formed of platinum iridium. In embodiments,the body may be formed of a cobalt chromium alloy. In embodiments, thebody may be formed of MP35N®. In embodiments, the body may be formed ofVitalium™. In embodiments, the body may be formed of Ticonium®. Inembodiments, the body may be formed of Stellite®. In embodiments, thebody may be formed of tantalum. In embodiments, the body may be formedof platinum. Materials disclosed with reference to the body or anycomponent of the device disclosed herein are not meant to be limiting.The skilled artisan will appreciate that other suitable materials may beused for the body or any other component of the device.

In embodiments, the body assembly is preferably formed from a length ofcylindrical tubing that is precut with slots at specific locations andthen formed in a series of processes to produce a shape suited for thepurpose of containing a flow control element within the interatrialseptum.

As an example, a first process might be to stretch the cylinder toexpand its internal diameter to a uniform target dimension. This can bedone with a balloon or a standard tubing expander consisting of asegmented sleeve and tapered conical inserts that increase the diameterof the sleeve when the cones are advanced toward the center. In orderthat the shape of the stretched tubing be preserved, the cylinder shouldbe annealed while held into this stretched shape by heating it beyond300° to 600° for at least about 20 minutes to allow the internalstresses to be relieved. A second process might be to form one flangeend shape using a similar process as the first process but using a toolshape specially designed for the first flange shape. A third processmight be to form the second flange end shape using a similar process asthe first process but using a tool specially designed for the thirdflange shape. These shapes must be annealed using a similar process asthe first shape, either in separate steps or altogether.

In embodiments, the internal diameter of the finished interatrialpressure vent is larger than about 5 mm to enable adequate venting ofthe left atrium and minimize damage to blood components from excessiveshear stress, but enabling the interatrial pressure vent to stow in aplacement catheter of smaller than about 14F.

In embodiments, the flow control element opening is at least about 50sq. mm. In embodiments, the flow control element opening is 50 sq.mm.+−10 sq. mm. In another embodiment, the cylindrical section is formedwith an inside diameter of between 3 and 15 mm.

The internal diameter of the body segment is preferably a constantdimension along the center, longitudinal axis of the interatrialpressure vent and is long enough to isolate the flow control elementfrom deflection or damage as a result of contact with other structuralelements of the heart.

In embodiments, the body segment is formed into a substantially toroidalshape, the inner diameter tapering down and then up again from one sideof the implant to the other. In embodiments, the length of the bodysection may be about 4 mm. In embodiments, the length of the bodysection may be between about 3 mm and about 40 mm.

In yet other embodiments, the flange segment may comprise at least asingle loop which is oriented to the cylindrical shape by at least about90° relative to the central axis of the cylinder and projected outwardto a distance away from the center axis of greater than the opening inthe atrial septum but at least about 3 mm further than the diameter ofthe inner cylinder.

In embodiments, the flange segment is formed of multiple struts thatextend radially outward, with respect to the center aspect of thecylinder. In embodiments, the flange struts each comprise asubstantially triangular shape that is wider adjacent to the bodysection than at the outer edge of the strut. In embodiments, the flangestruts comprise a substantially triangular shape that is wider adjacentto the body section than at the outer edge of the strut and contains anintegral hole at the outer edge for containing a radiopaque marker.

In embodiments, the flange segments comprise a substantially triangularshape that is wider adjacent to the body section than at the outer edgeof the segment and whose outer edge is rounded to reduce trauma againstthe tissue it contacts. In embodiments, the flange segments are formedfrom a single beam of material that projects outward from the centerlongitudinal axis of the body section. In embodiments, the flangesegment is formed of spiral shaped flange struts that are coplanar andsubstantially orthogonal to the central axis of the cylinder.

In embodiments, the flange segment is formed of at least one loopingmember that attaches to at least one portion of the body section. Inembodiments, the flange is preferably formed to automatically recoversubstantially to its preformed shape following partial deployment of theinteratrial pressure vent from the placement catheter. In this manner,the interatrial pressure vent will resist being pulled back through theseptal opening.

In embodiments, the flow control element device may be a tissue valve, asynthetic valve or a combination. The flow control element can be formedfrom animal or human tissue, such as bovine pericardial tissue. Theprocedures for obtaining these tissues and preparing them for use asimplanted valve components are well known to those skilled in the art.The flow control element could be a trileaflet valve, or also abileaflet valve, or also a simple flap valve. The flow control elementcould also be a ball and socket valve, a duckbill valve, a butterflyvalve, or any other valve component known to those skilled in the art.

In embodiments, the flow control element can be biased by adding aseparate component that is attached to at least one point along the bodyor flange segment and contacts against at least one point of the flowcontrol element surface at least at some point during its duty cycle.The component can be preformed to controllably affect the flow controlelement behavior. For example, in one embodiment, the flange segment canbe a looped wire formed from nitinol and connected to the body sectionand cantilevered against the surface of the flow control element facingthe left atrium and formed so that the surface of the flow controlelement is biased to be slightly open when the pressure is equal in theleft atrium and right atrium. Biasing can also be accomplished byvarying the stiffness of the material of the valve or componentsthereof.

In embodiments, a flange segment could be formed out of a helicalwinding of nitinol, with a core wire to connect one end of the flangesegment to the other end. In embodiments, the flow control element canbe preshaped to resist moving against pressure in one direction. Inembodiments, the flow control element could be biased to remain open ata predetermined pressure, or at a neutral pressure

In embodiments, the interatrial pressure vent consists of a body sectionand a flow control element; the body section comprising a cylindricalcore segment and two flanged end sections; the flow control elementbeing sealably secured to at least three points along the body section;the flanged end sections each comprising at least one flange segmentthat extends radially outward from the body section; the flow controlelement comprising at least one movable element that allows fluidpassage in one direction with lower resistance than another direction.In embodiments, the body section is elliptical in shape, or cylindriodand designed to offset asymmetric stress created by a linear septalopening.

In embodiments, the formed metal flange segments consist of at least twoflange segments, with at least one on each side of the septum. Inembodiments, the flange segments are positioned so they do not pinch theseptum between them, thereby reducing possible pressure necrosis. Inembodiments, the flange segments are shaped so the wall thicknessperpendicular to the septum is less than the wall thickness parallel tothe septum, thereby increasing flexibility without decreasing strength.

In embodiments, the flange segments are formed so the radius ofcurvature at the end is greater than about 0.03 inches. In embodiments,there is a radiopaque marker, preferably tantalum or platinum alloy,formed around, or integral with, the flange segment end to increaseradiopacity and increase the area of contact between the flange segmentand septum. In embodiments, the flange on the left atrium side of theseptum is bent at a shorter radius of curvature than the right atriumside.

In embodiments, the flange on one side of the interatrial septum isformed to return to greater than a 90° angle relative to the axis of thecenter cylinder. In embodiments, holes are preformed at a location alongthe cylindrical section for suture sites for securing the valvingdevice.

The above summary of the disclosure is not meant to be exhaustive. Othervariations and embodiments will become apparent from the descriptionand/or accompanying figures disclosed herein and below. The embodimentsdescribed above employ elements of each other and are meant to becombined with each other. For example, embodiments of flow controlelement may be used with differing configurations of the body element,flange, or segment thereof. While certain combinations are disclosed,the invention is not so limited

Other embodiments and advantages of the invention will become moreapparent from the following detailed description when taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully apparent from thefollowing description and appended claims, taken in conjunction with theaccompanying figures. Understanding that these figures merely depictexemplary embodiments, they are, therefore, not to be consideredlimiting. It will be readily appreciated that the components of thepresent disclosure, as generally described and illustrated in thefigures herein, could be arranged and designed in a wide variety ofdifferent configurations. Nonetheless, embodiments will be described andexplained with additional specificity and detail through the use of theaccompanying figures in which:

FIG. 1 is a schematic cross-sectional view of a patient's heart with aninteratrial pressure vent in situ;

FIG. 2 is an end view of the interatrial pressure vent of FIG. 1 in situas seen along line 2-2 of FIG. 1 ;

FIG. 2A is an end-on close up view of a flange segment of an embodiment;

FIG. 2B is an enlarged side cross-sectional view of an embodiment toillustrate variations in flexibility in a flange;

FIG. 3 is a cross-sectional side view taken along line 3-3 of FIG. 2 ;

FIG. 4 is perspective view of the body assembly of the interatrialpressure vent by itself;

FIG. 5 is a right side view of the body assembly of FIG. 4 ;

FIG. 6 is a distal end view of the body assembly of FIG. 4 ;

FIG. 7 is an enlarged fragmentary cross-sectional view taken along line7-7 of FIG. 6 ;

FIGS. 7A through 7C are a side elevational views of embodiments of thedevice in the stowed position;

FIG. 8 is a side elevational view of the interatrial pressure vent ofFIG. 1 in a collapsed configuration prior to loading in a placementcatheter;

FIG. 9 is a side view of the distal end of a placement catheter in itsopen position;

FIG. 10 is a side view of the distal end of a placement catheter in itsopen position and with an interatrial pressure vent in its stowedconfiguration and in position over the inner shaft of the catheter;

FIG. 11 is a side view of the distal end of a placement catheter in aclosed configuration with an interatrial pressure vent in its stowedconfiguration loaded onto the placement catheter;

FIG. 11A is a side view of another embodiment of a placement catheterwith an interatrial pressure vent stowed therein;

FIG. 12 is an exploded perspective view of the proximal and distal endsof a placement catheter;

FIG. 13 is a cutaway view of a heart of a patient and the distal end ofa placement catheter in position across the interatrial septum;

FIG. 14 is a schematic cross sectional side view of the proximal anddistal end of a placement catheter in a closed position and positionedacross the interatrial septum of the heart of a patient;

FIG. 15 is a view similar to FIG. 14 but showing the distal end of theplacement catheter in a partially open position and the distal flangesegments of the interatrial pressure vent deployed;

FIG. 16 is a view similar to FIG. 15 but showing the distal flangesegments of the interatrial pressure vent in position against the wallof the interatrial septum;

FIG. 17 is an enlarged cross-sectional detail view of the distal end ofthe placement catheter of FIG. 16 but showing the distal flange segmentsof the interatrial pressure vent being retracted from the interatrialseptum as if it were determined to be in an undesirable position byimaging the radiopaque markers and going to be redeployed;

FIG. 18 is a view similar to FIG. 16 but showing further deployment ofthe interatrial pressure vent by releasing the proximal flange segmentsif imaging determines a correct positioning of the distal flangesegments;

FIG. 19A is an enlarged cross-sectional detail view of the placementcatheter of FIG. 18 but showing the interatrial pressure vent fullyreleased in position and the placement catheter being removed;

FIG. 19B is schematic depiction of another embodiment of a placementcatheter system and interatrial pressure device along with thedeployment process therefor;

FIG. 19C is schematic depiction of another embodiment of a placementcatheter system and deployment process therefor;

FIG. 20 is a side elevational view of an alternate embodiment of aninteratrial pressure vent body with slanted flange segment ends;

FIG. 21 is a side elevational view of an alternate embodiment of aninteratrial pressure vent body with staggered flange segment ends;

FIG. 22 is a perspective view of an alternate embodiment of aninteratrial pressure vent body with an integrated retrieval means andthrombus clot strain;

FIG. 23 is a right side view of the body assembly of FIG. 22 ;

FIG. 24 is an end view of an alternate embodiment of interatrialpressure vent;

FIG. 25 is a cross-sectional side view taken along line 25-25 of FIG. 24;

FIG. 26 shows and alternate embodiment wherein the core segment 106 isovular rather than circular and thus the core segment is a cylindroid orelliptic cylinder rather than a simple cylinder;

FIG. 27 is schematic depiction of another embodiment of a placementcatheter system and interatrial pressure device along with thedeployment process therefor;

FIG. 27A is a side elevational view of the embodiment described inconnection with FIG. 27 in the stowed position;

FIGS. 28A through 28C depict other embodiments of the device that directthe flow of blood in a desired direction;

FIGS. 29A through 29C are an end-on view from the RA side of embodimentsof exit profiles of the flow control element;

FIG. 30 is a side view of an embodiment of the device having a tube-likeextension into the RA side of the heart;

FIG. 31 depicts an exploded view of a first embodiment of a mounting andloading tool for mounting and loading a prosthesis;

FIG. 32 depicts an exploded view of a second embodiment of a mountingtool for mounting a prosthesis;

FIGS. 33 and 34 depict the mounting tool with a prosthesis mounted;

FIG. 35 depicts an exploded view of a loading tool for loading aprosthesis on a mounting tool onto a delivery device;

FIG. 36 depicts the prosthesis being loaded into a catheter;

FIG. 37 depicts the loaded catheter with protective packaging;

FIGS. 38A and 38B depict an additional embodiment of a control device orhandle for deploying the prosthesis;

FIGS. 39A through 39E depict another embodiment of a control device fordeploying the prosthesis;

FIG. 40 depicts another embodiment of a control device or handle;

FIG. 41 depicts a retrieval device useful for retrieving a deployedprosthesis;

FIG. 42 depicts the retrieval device of FIG. 41 with a retrieval basketdeployed;

FIG. 43 depicts a closer view of the basket of FIG. 42 ;

FIGS. 44 and 45 depict retrieval devices using dilators; and

FIGS. 46A-49 depict additional embodiments of an implantable prosthesiswith retrieval and redeployment features: FIGS. 46A-46B; 47A-47B; and48A-48B depict front and side views of embodiments of implantableprostheses with retrieval and redeployment features; FIG. 49 illustratesa side view of an embodiment of an implantable prosthesis with retrievaland redeployment features.

FIG. 50 depicts anatomy of a human being and a human heart, withparticular focus on the pathways and natural lumens of the body;

FIG. 51 depicts a closer view of a heart and how guide wires andcatheters may be maneuvered in and around the heart to deployembodiments;

FIG. 52 depicts a first catheter extending from the superior vena cavato the coronary sinus of the heart;

FIG. 53 depicts an ablative catheter in the coronary sinus for creatingan opening into the left atrium of the heart;

FIG. 54 depicts the ablative catheter creating the opening;

FIG. 55 depicts a balloon catheter for expanding the opening;

FIG. 56 depicts a coronary sinus pressure relief stent in a non-deployedstate;

FIG. 57 depicts the stent of FIG. 56 in a deployed state;

FIG. 58 depicts a first embodiment of a flange for the atrial wall;

FIG. 59 depicts a second embodiment of a flange for the atrial wall;

FIG. 60 depicts another embodiment of a stent suitable for ensuringcommunication between the right atrium and the coronary sinus;

FIG. 61 depicts details of a stent with a one-way valve; and

FIGS. 62A and 62B depict another embodiment of a stent.

DETAILED DESCRIPTION

Certain specific details are set forth in the following description andFigures to provide an understanding of various embodiments. Those ofordinary skill in the relevant art will understand that they canpractice other embodiments without one or more of the details describedbelow. Finally, while various processes are described with reference tosteps and sequences in the following disclosure the steps and sequencesof steps should not be taken as required to practice all embodiments ofthe present disclosure.

As used herein, the terms “subject” and “patient” refer to any animal,such as a mammal like livestock, pets, and preferably a human. Specificexamples of “subjects” and “patients” include, but are not limited, toindividuals requiring medical assistance, and in particular, requiringtreatment for symptoms of heart failure.

As used herein, the term “pressure differential” means the difference inpressure between two points or selected spaces; for example between oneside of a flow control element and another side of the flow controlelement.

As used herein, the term “embolic particle” means any solid, semi-solid,or undissolved material, that can be carried by the blood and causedisruption to blood flow when impacted in small blood vessels, includingthrombi.

As used herein, the terms “radially outward” and “radially away” meansany direction which is not parallel with the central axis. For example,considering a cylinder, a radial outward member could be a piece of wireor a loop of wire that is attached or otherwise operatively coupled tothe cylinder that is oriented at some angle greater than 0 relative tothe center longitudinal axis of the cylinder.

As used herein, the term “axial thickness” means the thickness along anaxis parallel to the center longitudinal axis of a shape or component.

As used herein, the term. “axial direction” means direction parallel tothe center longitudinal axis of a shape or component.

As used herein, a “sealable connection” is an area where componentsand/or objects meet wherein the connection defines provides for aninsubstantial leakage of fluid or blood through the subject area.

As used herein, the term “lumen” means a canal, duct, generally tubularspace or cavity in the body of a subject, including veins, arteries,blood vessels, capillaries, intestines, and the like.

As used herein, the term “sealably secured” or “sealably connected”means stably interfaced in a manner that is substantially resistant tomovement and provides resistance to the flow of fluid through or aroundthe interface.

As used herein, the term “whole multiple” means the product contains nodecimal.

The present disclosure provides structures that enable several uniqueintracardiac and intraluminal valve devices, loaders, controls andplacement devices and catheters therefor. In some embodiments directedtoward the intra-cardiac setting, these valve devices are intended toallow sufficient flow from the left atrium to the right atrium torelieve elevated left atrial pressure and resulting patient symptoms butalso prevent the amount of flow from the right atrium to the left atriumto minimize the potential for thrombi or other embolic material fromentering the arterial circulation.

However, it should be appreciated that embodiments are applicable foruse in other parts of the anatomy or for other indications. Forinstance, a device such as that described in this disclosure could beplaced between the coronary sinus and the left atrium for the sameindication. Also, a pressure vent such as is described in thisdisclosure could be placed between the azygous vein and the pulmonaryvein for the same indication.

Referring now to FIG. 1 , one embodiment is used as an interatrialpressure vent. FIG. 1 depicts the heart of a human subject. “LA” refersto the left atrium, and “RA” refers to the right atrium. The interatrialseptum is depicted as 107. Interatrial pressure vent 100 includes a bodyelement 101 and flow control element 104, embodiments of which will bedescribed in further detail below. The body element 101 comprisesflanges 102 and 103. In this and other embodiments described herein,flanges 102 and 103 may be annular flanges, which define a gap 2000 intowhich the septum 107 fits. In embodiments, after insertion, theinteratrial pressure vent is securely situated in an opening created inthe interatrial septum. Arrow F in FIG. 1 shows the direction of flow.It can be thus seen that a build up of pressure in the LA can be vented,by way of the inventive device, to the RA.

Referring now to FIG. 2 , an embodiment of the interatrial pressure ventis illustrated. Interatrial pressure vent 100 includes body element 101comprising a substantially open mesh and including a substantiallycylindrical core segment (shown end on) 106 and substantially annularflanges 102 and 103. Flanges 102 and 103 may be comprised of any numberof flange segments (or “flange elements” or “flange members”) 102 a-102h and 103 a-103 h, that are attached adjacent to the end of the coresegment and extend radially outward from longitudinal axis of the coresegment and flow control element 104. “Flange segments” may also bereferred to as “legs” herein. The flanges 102 and 103 (and thus thesegments which comprise them 102 a-h and 103 a-h) in this and allembodiments disclosed herein, may also be integral with the coresegment. That is, they need not be necessarily “attached” thereto butmay be fabricated from the same material that defines the core segment(including in the manners described above and herein) and thus may becontiguous therewith. The flow control element may be attached to thebody element, for example at locations 105. The flange segments in thisand any embodiment of any annular flange may be formed of two individualstrut elements or also can be formed of a single element. The flangesegments may be generally rectangular in cross section, circular incross section, oval in cross section or some other geometric shape.

In embodiments, the flange segments are designed to be more flexiblethan the core segment. In such embodiments, the increased flexibilitymay be achieved in several ways. In embodiments, a dimension of thesurface of the strut elements that make up the flange segments isaltered relative to the corresponding dimension of the struts (orelements, or members) that make up the core segments. FIG. 2Aillustrates such embodiments. FIG. 2A shows an example flange segment103 a viewed end on. As shown, the end-facing dimension of strut elementof 103 x has a width D. By decreasing the width D in relation to thewidth of the outward-facing dimension of the struts that comprise thecore segment, an increased flexibility of the flanges in relation to thecore segment or other flange members (or portions thereof) can beachieved. FIG. 2B shows an enlarged fragmentary cross-section of anembodiment of the device substantially shown in FIG. 6 . The view istaken along line 7-7 of FIG. 6 . In this figure, the cross hatched areashows the area of increased flexibility. It can be seen that one area ofthe flange segment is thus more flexible than another area. Inembodiments where the strut elements are circular, then in a similarfashion, the diameter of the strut element could be made to have adiameters less than the diameter of the strut (or similar elements)comprising the mesh-like configuration of the core segment.

In embodiments where the flange element is made from a different sectionof material and is attached to the core segment, the segment materialcould be chosen to have a greater flexibility than the core segment (orremaining portion of the flange segment or flange itself as the case maybe). The choice of materials based on their flexibility will be apparentto those skilled in the art. In the ways described above, the flangesegments can achieve greater flexibility than the core segment (or theremaining portion of the flange segment or the flange itself as the casemay be) thereby reducing probability of damage to the tissue of theseptum while allowing the core segment to maintain a strong outwardforce against the septal opening and thus decrease the probability thatthe device could become dislodged.

In embodiments having an open-mesh configuration for the body element101, the body element can be formed from a number of materials suitablefor use in a patient, such as titanium, nitinol, stainless steel,Elgiloy®, MP35N®, Mobilium, Ticonium, Platinore, Steilite®, tantalum,platinum, or other resilient material. Alternatively, in suchembodiments, the body element 101 can be formed from a polymer such asPTFE, UHMWPE, HDPE, polypropylene, polysulfone, or other biocompatibleplastic. The surface finish of the body element may be smooth with noedges or sharp discontinuities. In other embodiments, the surface finishis textured to induce tissue response and tissue in growth for improvedstabilization. In embodiments, the open mesh of body element 101 can befabricated from a resorbable polymer such as polylactic acid,polyglycolic acid, polycaprolactone, a combination of two or more ofthese or a variety of other resorbable polymers that are well known tothose skilled in the art.

In embodiments, the structure of the body element may be uniform andmonolithic.

In other embodiments, the body element (mesh or monolithic) comprisesporous materials to encourage tissue ingrowth or to act as a reservoirfor containing one or more compounds that will be released over timeafter implant to address numerous issues associated with the productperformance. These compounds can be used to diminish calcification,protein deposition, thrombus formation, or a combination of some or allof these conditions. The compound can also be used to stimulate anirritation response to induce tissue ingrowth. In embodiments, thecompound can be an anti-inflammatory agent to discourage tissueproliferation adjacent to the device. Numerous agents are available forall of such uses and are familiar to those who are skilled in the art.

In embodiments, the material that comprises the body may be multilayeredcomprising a coating of resorbable polymer or semipermeable polymer thatmay comprise various compounds that may be released, and in someembodiments in a controlled manner over time, after implant to addressnumerous issues associated with product performance.

The mesh can be formed from wire that is pre-bent into the desired shapeand then bonded together to connect the component elements either bywelding them or adhesively bonding them. They could be welded using aresistance welding technique or an arc welding technique, preferablywhile in an inert gas environment and with cooling control to controlthe grain structure in and around the weld site. These joints can beconditioned after the welding procedure to reduce grain size usingcoining or upset forging to optimize fatigue performance.

In other embodiments, the mesh can be formed from a hollow tube that hasbeen slotted using, for example, a machining laser or water drill orother method and then expanded to form the open structure, if asufficiently elastic and resilient material, such as nitinol, is used,the structure can be preformed into the finished shape and thenelastically deformed and stowed during delivery so the shape will beelastically recovered after deployment. The surface of the finishedassembly must be carefully prepared to insure is passivated and free ofsurface imperfections that could be a nidus for thrombus formation.

In embodiments, the flow control element 104 is a tissue valve such as atricuspid valve, a bicuspid valve or a single flap valve formed frompericardial tissue from a bovine, porcine, ovine or other animal. Anynumber of cusps may be used. The flow control element is formed using anumber of processing steps and auxiliary materials such as are wellknown in the art.

The flow control element 104 can also be a ball valve, a duckbill valve,a leaflet valve, a flap valve, a disc in cage type valve, a ball in cagetype valve or other type of valve formed from a polymer or polymers or acombination of polymers, ceramics and metals such as Dacron (polyester),PTFE (such as Teflon®), polyurethane, PET or other suitable polymer;titanium, stainless steel, nitinol, MP35N®, cobalt-chromium-nickel alloy(such as Elgiloy®), or other suitable metal; zirconia, silicone nitride,or other suitable ceramic. Valves or portions thereof may comprisedifferent stiffness/flexibly properties with respect to other valves orportions thereof in the flow control element.

The flow control element 104 preferably extends to a point along theflange assembly 103 to enable creation of a sealable connection to theseptum wall after placement. This is more particularly shown in FIG. 3where it can be seen that in embodiments, the flow control elementextends beyond the length of the core segment and is folded and attachedto the core segment so as to create a lip that extends in a directioncenter of the opening in the vent. When the device is abutted againstthe septal wall, this lip forms said sealable connection and thus canreduce the likelihood that blood can flow through the septal opening viapathways between the outer surface (septal-facing surface) of theinteratrial pressure venting device and the septal opening. The flowcontrol element 104 is attached to the body element 101. This can beaccomplished by using a suture material, such as silk, nylon,polypropylene, polyester, polybutylester or other materials such as arewell known to those skilled in the art. In embodiments, flow controlelement 104 can be attached to body element 101 using adhesive bondingagents such as cyanoacrylate, polymethylmethacrylate, or other materialssuch as are well known to those skilled in the art. In otherembodiments, flow control element 104 can be attached to body element101 via staples, rivets, rings, clamps or other similar methods as arewell known to those skilled in the art.

As mentioned above, flow control element can be made of materialselected for its flexibility/stiffness. In embodiments where a loosevalve is desired that resonates more closely with the cycle of theheart, a however stiffness material may be chosen. In embodiments whereit is desired to open the valve when the pressure differential reaches aselected value, the material of the flow control element can be selectedand/or processed in a manner to open at the desired differential. Theleaflets or sections of the flow control element itself may alsocomprise areas of variable stiffness, and or may be more flexible orless flexible than other leaflets or components of the flow controlelement.

FIG. 3 shows the device implanted in the atrial septum of the heart of apatient. As can be seen from the figure, the core segment 106 can beformed contiguously with flanges 102 and 103 and thus flange segments102 a-102 h and 103 a-103 h respectively. In the embodiment shown, flowcontrol element 104 is contained within the core segment 106 so it doesnot extend beyond the face of the body element 101, thereby insulatingit from contact from other body structures or peripheral tissue. Inembodiments, the core segment 106 can be extended to protrude beyond theinteratrial septum 107 and the flange assembly 102 and/or 103 on atleast one side of the interatrial septum 107 and can be formed with ashape that extends to create a lip in the manner described above. Inembodiments, the ends of the flange assemblies 102, 103 are formed tolie at a parallel angle to and against the septal wall along at least apart of its length to increase the area of contact and thereby decreasethe stress concentration against the septal wall.

Referring now to FIG. 4 , an embodiment of the body element is shown.This perspective view of the body element 101 shows how, in embodiments,the ends of flange segments 102 a-102 h, 103 a-103 h are rounded attheir distal ends 115 and 116 to reduce stress concentrations againstthe interatrial septum after placement. This rounded shape can easily beformed as part of the integral shape of the flange segment. In otherembodiments, the thickness of the segment in this area may be decreasedto decrease the stress further against the interatrial septum, which issimilar to embodiments described above. Also similar to embodimentsdescribed above, if the segment is round, the diameter can be decreasedin order to increase flexibility. Also, as described above a differentmaterial of higher flexibility could be used for the end portions of thesegments.

While rounded shapes at the ends of the flange segments reduce stress onthe septum, other variations on this theme are contemplated. FIGS. 7Athrough 7C illustrate embodiments where the shape of the end portions ofthe flange segments has configurations to achieve less stress againstthe septal wall—among other goals. FIG. 7A is a side elevational view ofembodiment of the pressure venting device in its stowed configuration.Core segment 106 of body element 101 is shown and, in this embodiment,is integral with flanges 103 and 102. The individual flange segments arenot labeled; however, it is easily seen that flange 103 comprisessegments substantial similar to those described above. There is noeyelet or opening at the end of the segment in the embodiment shown.Flange 102 shows an embodiment where the flange segment is not comprisedof a triangular or multi-strut arrangement as described above but rathera single-member segment. Any flange may be constructed withsingle-member segment. An example single member is referred to as 103 s.In this example, at the end of each single-member flange segment (102 s)for example, there is an eyelet. FIG. 7B shows an embodiment similar tothat shown in FIG. 7A where the end of the segments 102 s are noteyelets but rather pads. FIG. 7C shows another embodiment where the endsof the segments 102 are paddle shaped. Other smooth-edged shapes couldbe used, and it should be understood that such shapes and configurationsapply to all manner of flange segment ends, not only single-membersegments. This would include the ends of flange segments shown anddescribed herein, for example with reference to FIGS. 2 through 7 .

FIGS. 7A-C also show embodiments having at least one flange segmentbeing longer than the other flange segments. Again, while represented assingle-member flange segments they need not be and as such aconfiguration with at least one longer segment may apply to anyflange-segment configuration disclosed herein. The benefits and purposeof having at least one longer flange segment will be described morefully below.

In embodiments, the outer ends of the flange segments 102 a-102 h, 103a-103 h are formed with integral marker holes or slots 109 and 110(shown in FIGS. 3 and 7 for example) in which markers 118 and 119 can bepositioned so the device may more easily be visualized usingradiographic imaging equipment such as with x-ray, magnetic resonance,ultrasound or other imaging techniques. Markers as disclosed herein maybe applied to the ends of any segments, not just those with holes oreyelets therein. A radiopaque marker 118 and 119 can be swaged, riveted,or otherwise placed and secured in the hole and thereby dimensioned tobe flush with the end of the segment. Markers may also be simplyattached or to end of a segment not having a hole. In all embodimentshaving markers, flange ends 115 and 116 are more visible when imaged. Inother embodiments, the markers 118 and 119 can be bonded with anadhesive agent such as cyanoacrylate or epoxy or a variety of othermaterials that are available and suitable for implant as are well known.The markers may be proud (as shown for example in FIG. 7 ) or flush withthe end of the flange segment. The radiopaque markers 118 and 119 may beformed of tantalum, tungsten, platinum iridium, gold, alloys of thesematerials or other materials that are known to those skilled in the art.Also markers 118 and 119 comprising cobalt, fluorine or numerous otherparamagnetic materials or other echogenic materials that are known tothose skilled in the arts can be incorporated together with theradiopaque materials, or in alternating locations of the flange segmentsto enable both x-ray and echographic imaging of the interatrial pressurevent. Alternatively, the ends of the flange elements 102 a-102 h and 103a-103 h can be wrapped with a foil made of the same marker materials. Inembodiments, the radiopaque material can be laminated to the flangesegments and bonded through a welding process or using an adhesive suchas cyanoacrylate or numerous other adhesives known to those skilled inthe art.

Suture rings 117 can be formed in the body element to locate and fix theattachment site along the body element to the flow control element. Thesuture rings can be circular holes formed into the structure or theycould also be some other shape such as rectangular or triangular andalso can be formed as a secondary step, for example by standardmachining techniques, using a secondary laser machining step, or withelectro-chemical etching. Preferably the connection between a segmentand any other segment of the body element are formed with as large aradius as possible to increase resistance to fatigue failure. Also,preferably, all edges of the formed device are rounded to improvebiocompatibility and hemocompatibility.

The pattern of suture rings as well as which of the rings are selectedduring suturing may affect the properties of the flow control element.For example, in embodiments where it is desired to have the flow elementloose and flappable, less suture rings may be utilized and, in suchembodiments, RA-side end of the flow control element may containrelatively less sutures than the LA side. In other embodiments, it maybe desirable to keep the flow control element affixed to the coresegment for a increased length of the segment thereby reducing theamount of flow control element material that affecting flow. Still inother embodiments the top or bottom portion the flow element at the RAside may be sutured in such a way so as to allow the top or bottomportion of the flow control element to affect flow more than the otherportion respectively. Embodiments discussed below where the flow is“aimed” may utilize suturing patterns effective to enable the desiredflow control element configuration.

Returning to the flange segments, in an embodiment, the interatrialpressure vent 100 is comprised of an equal number of flange segments oneach side of the interatrial septum. In embodiments, there are eightflange segments on each side of the core segment. In another aspectthere are an equal number of suture rings and flange segments on oneside of the interatrial pressure vent. In other embodiments, there areseven flange segments on each side of the core segment. In otherembodiments, there are six flange segments on each side of the coresegment. In other embodiments, there are five flange segments on eachside of the core segment. In other embodiments there are four flangesegments on each side of the core segment. In other embodiments thereare three flanges on each side of the core segment. In other embodimentsthere are two flanges on each side of the core segment. In otherembodiments, there is one flange on each side of the core segment. Stillin other embodiments there are more flange segments as compared toflange segments. And in other embodiments, there are more flangesegments as compared to flange segments. As can be seen there are anumber of variations for the number of flange segments and the skilledartisan will appreciate that any number could be used while notdeviating from the scope and spirit of this disclosure.

Referring now to FIG. 5 , the body element of an embodiment is displayedin side view. The flange segments can be formed to produce a gap G (alsoreferred to as an annular gap) between the ends of flange segments onone side of the body and flange segments on the other side of the body,when the device is in its “native” or un-deployed state. When the deviceis deployed, it flexes to accommodate the tissue and as such the gap mayexpand when tissue is positioned therein. In embodiments, this gap isslightly smaller than the thickness of the interatrial septum. In otherembodiments, the gap can be larger than the thickness of the interatrialseptum. In other embodiments the gap can be zero. In another aspect thegap can be negative: in this case the flange segments on each side ofthe body can be formed to cross each other in order to exert morepressure between the deployed flange segments and the interatrialseptum. Also shown in FIG. 5 are radiopaque markers 118 and 119, whichin embodiments are shown to be located adjacent to the end of the flangesegments.

Referring now to the embodiment shown in FIG. 6 , the flange segments102 a-102 h are oriented so they are not directly opposed to flangesegments 103 a-103 h on the opposite side of the body element so thatafter placement there is no pinching points thereby reducing the chancefor tissue injury. In embodiments, flange segments 102 a-102 h arearranged midway between adjacent ends of flange segments 103 a-103 h. Inembodiments the length of flange segments 102 a-102 h are similar to thelength of flange segments 103 a-103 h. However in other embodiments thelength of flange segments 102 a-102 h are identical to the length offlange segments 103 a-103 h; the length of flange segments 102 a-102 hare longer than 103 a-103 h; and the length of flange segments 102 a-102h are shorter than flange segments 103 a-103 h.

Referring now to FIG. 7 , in embodiments having radiopaque markers itcan be seen that the radiopaque markers 118 and 119 may be placed intothe marker holes 109 and 110 (or placed on the ends of flange segmentsthat do not have holes) to locate the ends of the flange segments 102a-102 h and 103 a-103 h with a non-invasive imaging technique such aswith x-ray or echosound during or after the procedure. In embodiments,the markers 118 and 119 can be formed to be flush in an axial directionwith the outer surface and the inner surface of the flange segments 102a-102 h and 103 a-103 h. In another aspect, the markers 118 and 119 canbe formed to extend in an axial direction beyond the outer surface ofthe flange segments 102 a-102 h and 103 a-103 h, away from theinteratrial septum. In embodiments, the markers 118 and 119 can beformed to extend in an axial direction beyond the inside of the flangesegments 102 a-102 h and 103 a-103 h, toward the interatrial septum. Inembodiments, the markers 118 and 119 can be formed to extend in an axialdirection beyond the inside and the outside of the flange segments 102a-102 h and 103 a-103 h. In embodiments, the markers 118 and 119 can beformed to be recessed in an axial direction within the surface of theinside of the flange segments 102 a-102 h and 103 a-103 h. Inembodiments, the markers 118 and 119 can be formed to be recessed in anaxial direction within the outside of the flange segments 102 a-102 hand 103 a-103 h. In embodiments, the markers 118 and 119 can be formedto be recessed in an axial direction within both the inside and theoutside of the flange segments 102 a-102 h and 103 a-103 h. Inembodiments, the markers 118 and 119 can be formed to extend in a radialdirection within the width of the flange segments 102 a-102 h and 103a-103 h. In embodiments, the markers 118 and 119 can be formed to extendin a radial direction flush with the width of the flange segments 102a-102 h and 103 a-103 h.

Referring now to FIG. 8 , an interatrial pressure vent 100 is shown inits stowed configuration. In embodiments, the interatrial pressure ventcan be collapsed to a substantially cylindrical shape for stowing in adelivery catheter during placement. Flange segments 102 a-102 h and 103a-103 h can be fabricated to be substantially equal in length. The“stowed position” is not meant to apply only to devices having flangesegments of equal length but rather to all embodiments of the ventingdevice disclosed herein. Devices having flange segments of varyinglength and orientation such as those described herein are also designedto stow in substantially the same manner as shown in FIG. 8 . In anembodiment 200 seen in FIG. 20 , flange segments 202 a-202 h and 203a-203 h are formed on a slanted angle so that, when marker elements aresecured to the ends of the flange segments, the flange segments can bestowed into a smaller volume. In embodiments 300 seen in FIG. 21 ,flange segments 302 a-302 h are formed of alternating length to allowstowage into a smaller volume.

Referring now to FIG. 9 , an embodiment of the distal end of theplacement catheter 111 is shown in its open position. The inner shaft112 is fabricated with a center lumen 136 of sufficient diameter tocontain a guidewire 138 or also for use in injecting contrast or otherliquid. Commonly, the lumen would be sized for a guidewire of 0.010″,0.011″, 0.014″, 0.018″, 0.021″, 0.028″, 0.035″, 0.038″, 0.042″ or0.045″. This lumen 136 can also be used to measure pressure at thedistal end of the catheter using other equipment and techniques that arewell known to those skilled in the art. The lumen 136 preferably extendsthrough the entire length of the inner shaft 112. Alternatively, theguidewire lumen 136 can extend for a shorter length in the proximaldirection and then through a side hole (not shown) of the inner sheath.A corresponding side hole (not shown) is placed on the outer shaft 113adjacent to the side hole in the inner shaft 112 to create a pathwaybetween the center lumen 136 of the inner shaft 112 and the outside ofthe outer shaft 113. In this way it is possible to pass a guidewire fromthis distal end of the inner lumen 136 through the side hole andexchange the catheter over a guidewire that is less than twice thelength of the catheter 111 while securing the guidewire position duringexchange.

In embodiments, the inner shaft 112 is configured with a waist section120 to contain the folded interatrial pressure vent 100 between the gapformed in the space outside of this section of inner shaft 112 and theinside of the outer shaft 113. The inner shaft 112 may be formed tocontain at least one circumferential groove 114 at the proximal end ofwaist section 120 that forms a recess between the inside of the outershaft 113 and the smallest diameter of the groove that is greater thanthe gap formed in the space between the waist section 120 and the insideof the outer shaft 113. Radiopaque markers 118 can extend in a radialdirection past the outer surface of the flange segments 102 a-102 h andin embodiments, when interatrial pressure vents are folded into theirstowed configuration and placed into position over inner shaft 112,radiopaque markers 118 are dimensioned to fit into groove 114. Othersimilarly dimensioned sections may be used; that is, that which fitsinto the groove need not necessarily be a radiopaque marker. Inembodiments, when interatrial pressure vents are stowed in this manner,the gap between waist section 120 and the inside of outer shaft 113 isnot sufficient to allow radiopaque markers 118 beyond the distal end ofgroove 114 unless the outer sheath 113 is retracted beyond the proximalend of groove 114.

The inner shaft 112 may be formed with a groove 121 on the distal end ofthe waist section 120 adjacent to the location of the distal end of theinteratrial pressure vents are radiopaque markers 119 (or similardimensioned members) can extend in a radial direction past the outersurface of the flange segments 102 a-102 h and in embodiments, wheninteratrial pressure vents are folded into its stowed configuration andplaced into position over inner shaft 112, radiopaque markers 119 aredimensioned to fit into groove 121. In another aspect, the inner shaft112 may be formed with a circumferential groove 114 on the proximal endof waist section 120 and a circumferential groove 121 on the distal endof the waist section 120 The inner shaft can be formed of a variety ofpolymers or metals or combinations of polymers and metals that aresuitable for use in a patient. The inner shaft can be fabricated from asingle length of PTFE, PEP, HDPE, LDPE, polypropylene, acetal, Delrin,nylon, Pebax, other thermoplastic rubber, aliphatic or aromaticpolyurethane, or a variety of other engineering resins that are wellknown to those skilled in the art. In embodiments, the inner shaft canbe fabricated using multiple layers of two or three of theabove-mentioned polymers to combine desirable properties of each. Forexample, the outer surface could be composed of polyurethane to enableeasier bonding of auxiliary components to the inner shaft. The innerlayer could be PTFE to convey better lubricity to the inner shaft. Inembodiments, the inner shaft and or the outer shaft could be coated onthe inner and or outer surface with a coating material that conveysspecific properties to the shaft like antithrombogenicity or lubricity.There are numerous available coating materials suitable for thesepurposes as are well known to those skilled in the art. The inner shaftcan be compounded with a radiopacifier to increase the visibility of theinner shaft under fluoroscopy using bismuth salts such as bismuthsubcarbonate, bismuth oxychloride, bismuth trioxide, tungsten powder,molybdenum powder or other radiopacifier such as are well known to thoseskilled in the arts. Similarly, the outer sheath can be fabricated fromthe same set of materials as the inner sheath, in the same manner andusing the same coatings. Embodiments described below in connection witha flange rather than circumferential groove operate in substantially thesame manner as described above and herein, except the device does notnecessarily have projections that fit into and are retained by thegrooves.

Referring now to FIG. 10 , a folded representative interatrial pressurevent 100 is shown in its stowed position with the placement catheter 111shown in its open position. In practice, if the body of the interatrialpressure vent is fabricated of nitinol or other elastic material, whenthe placement catheter is in its fully open position, the flangesegments 102 a-102 h and 103 a-103 h would automatically recover into ashape like that shown in, for example, FIG. 4 , hence this Figure isshown to illustrate the position of the interatrial pressure vent 100relative to the waist section 120 and grooves 114 and 121. Whenradiopaque markers (or similarly dimensioned members) 118 extend beyondthe thickness of the inside of body segment 101 of interatrial pressurevent 100, they form a projection within interatrial pressure vent 100that can be captured within groove 114 to secure the position of theinteratrial pressure vent 100 during placement. During deployment, theouter shaft 113 of placement catheter 111 is retracted a sufficientdistance to reveal the distal portion of the interatrial pressure vent100 allowing the flange segments 103 a-103 h to dilate radially awayfrom the central longitudinal axis of body 101. By capturing theradiopaque 118 markers within the groove 114, the device can berepositioned easily without further deployment, or the device can becompletely retracted and removed from the patient without deployment asindicated in FIG. 17 .

Referring now to FIG. 11 , an interatrial pressure vent 100 is showncompletely stowed within the placement catheter 111.

FIG. 11A shows an embodiment of the placement catheter similar inoperation to those described herein but operative to engage aninteratrial pressure vent by way of a slightly different mechanism thandescribed above in connection with circumferential grooves. This figureshows a schematic depiction of a stowed interatrial vent. Rather thanhaving the grooves as described above, this embodiment of a placementcatheter comprises an inner shaft having a flange or member 3000 (ratherthan a groove) which has a diameter larger than that of the inner shaftto grip and hold an end of the interatrial vent device as shown. Asshown in the figure, the flange and its segments (collectively referredto in the figure as 102) wrap around the ball-shaped flange 3000 andallow the interatrial pressure vent to be moved with the placementdevice in the manners described herein.

Referring now to FIG. 12 , a placement catheter 111 is shown. It shouldbe noted that while the inner shaft is depicted as having grooves inFIG. 12 , the inner shaft may comprise the flange 3000 as describedabove in connection with FIG. 11A. The skilled artisan will appreciatethat the operation of the device is substantially similar whethergrooves or flanges are utilized. The placement catheter 111 comprises afirst handle component 128 that can be attached to outer shaft 113. Thefirst handle component can be attached to the outer shaft 113 using avariety of adhesive methods such as solvent bonding using a solvent forboth the handle and outer shaft material; an organosol consisting of asolvent and polymer in solution that is compatible with both the outershaft and the first handle component; a polymerizable adhesive, such aspolyurethane, cyanocrylate, epoxy or a variety of other adhesives as arewell known to those skilled in the art. The first handle component canbe fabricated from a variety of metals such as aluminum, stainlesssteel, titanium or a number of other metals and alloys as are well knownto those skilled in the art. In embodiments, the first handle component1:28 is fabricated from a polymer such as polycarbonate, or a variety ofengineering resins, such as Lexan®, or others as are well known to thoseskilled in the art.

The first handle component comprises hand grip section 124 and tubularshaft section 125. The tubular shaft section 125 can contain keyway 122that is formed or machined into the shaft section. The keyway ispreferably formed with three linear sections; a first linear section131, a second linear section 132 and a third linear section 133. Each ofthese sections is formed to traverse along a path primarily parallelwith the center axis along the length of the first handle component buteach is displaced radially from one another by at least about half ofthe width of the keyway. The placement catheter 111 also can comprise asecond handle component 129 that can be attached to inner sheath 112.The second handle component can be fabricated from the same variety ofmetals and polymers as the first handle component. The two handles canbe fabricated from the same materials or from different materials. Thesecond handle component can be attached to the inner sheath in the samemanner and using the same materials as the first handle componentattaches to the outer sheath. In embodiments, the second handlecomponent can contain threaded hole 126 for containing set screw 127.The set screw can be twisted to capture the inner shaft against thesecond handle component. The second handle component 129 also cancomprise a second hand grip section 134 and second tubular shaft section130. The second tubular shaft section can contain key 123 that is formedor machined of suitable dimension to adapt to keyway 122 of first handlecomponent 128. When assembled, second handle component 129 can beslideably moved relative to first handle component 128 in a mannercontrolled by the shape and length of the key way 122. As the secondhandle 129 is advanced relative to the first handle 128, it can beappreciated that be inner sheath 112 will slide in a distal directionout from the outer sheath 113. It can be appreciated that when thesecond handle component 129 is assembled, the key 123 is slid into thefirst linear section 131 and advanced until it hits the edge of thekeyway formed between the first linear section 131 and the second linearsection 132. In order for the second handle component 129 to advancefurther, it must be rotated and, once rotated, it can be advancedfurther but will stop when the key 123 hits the edge of the keywayformed between the second linear section 132 and the third linearsection 133. The keyway dimensions are preferably selected withconsideration for the combination of lengths of other components in theplacement device.

A first position, defined as the position when the key 123 is in contactwith the proximal edge formed between the first linear section 131 andthe second linear section 132, is preferably determined so, when fullyassembled and with the interatrial vent in its stowed position withinthe placement catheter, the outer shaft 113 will completely cover thelength of the interatrial pressure vent 100 as is desired duringcatheter placement. The keyway dimensions can also be selected to resultin a second position, defined as the position when the key 123 is incontact with the distal edge formed between the second linear section132 and third linear section 133. The second position would preferablybe selected to reveal the full length of flange segments 103 a-103 h butretain flange segments 102 a-102 h within the outer shaft 113 of thecatheter. The length of the third linear section 133 would preferably beselected so that, when the second handle component 129 was advancedcompletely against the first handle component 128, the full length ofthe interatrial vent 100 would be uncovered by the outer shaft 113 andthe device would be deployed. A variety of other configurations of thefirst and second handle components could be used for this same purpose.The first handle component tubular shaft section 125 and the secondhandle component tubular shaft section 130 could be threaded (not shown)so the first handle component 128 could be screwed into the secondhandle component 129. Alternatively, gear teeth (not shown) could beformed in the first tubular shaft section 125 of the first handlecomponent 128 and a gear wheel (not shown) could be incorporated intothe second shaft tubular section 130 of the second handle component 129.The gear wheel would preferably be chosen to mesh with the gear teethand the second handle component 129 could be advanced toward the firsthandle component 128 by rotating the gear wheel. A variety of otherdesign configurations could be utilized to control the relative locationbetween the first handle component and the second handle component asare well known to those skilled in the art.

FIGS. 13 through 17 show embodiments of a system for treating heartfailure. More specifically FIGS. 12 through 19 show how the placementcatheter is introduced and positioned in a patient and methods forplacing the interatrial valve in a patient. The interatrial pressurevent 100 is presterilized and packaged separately from the placementcatheter 111. Sterilization can be performed by exposing the device to asterilizing gas, such as ethylene oxide, by exposing the device toelevated temperature for an adequate period of time, by using ionizingradiation, such as gamma rays or electron beam or by immersing thedevice in a fluid that chemically crosslinks organic molecules, such asformaldehyde or glutaraldehyde and then rinsed in sterile water orsterile saline. For each of these sterilization methods, considerationmust be given to compatibility of the materials so device performance isnot adversely affected as a result of the sterilization process. Also,the packaging design and materials must be carefully considered with thesterilization procedure, post sterilization handling and storage,environmental exposure during storage and shipment, and ease ofhandling, opening, presentation and use during the procedure.

In embodiments, interatrial pressure vent 100 can be assembled usingcomponents that have been pre-sterilized using one of the above methodsor others that are well known and the final assembly may be accomplishedin an aseptic manner to avoid contamination.

In embodiments, the interatrial pressure vent 100 can be suppliednon-sterile and be sterilized around the time of use using one of theabove methods or by other methods well known by those skilled in theart.

Similarly, the placement catheter 111 may be pre-sterilized and packagedseparately from the interatrial pressure vent 100. Sterilization can beperformed using a similar method to the interatrial pressure vent 100 orusing a different method from the same choices or using some othermethod as is well known by those skilled in the art.

In embodiments, an interatrial pressure vent 100 and the placementcatheter 111 can be supplied pre-sterile and in the same package. Inanother aspect, the interatrial pressure vent 100 and the placementcatheter 111 can be preloaded and supplied pre-sterile.

Prior to insertion, the interatrial pressure vent 100 is preferablyfolded and stowed onto the placement catheter 111. This can beaccomplished in a sterile field and using aseptic techniques in thefollowing steps. First the interatrial pressure vent 100 is presented tothe sterile field and the placement catheter 111 is presented to thesterile field. Second, the interatrial pressure vent 100 and placementcatheter 111 are inspected for visible signs of damage, deterioration orcontamination. Third, the second handle component 129 of the placementcatheter 111 is retracted fully so the outer shaft 113 exposes the innershaft 112 to the maximum extent allowed. Fourth, the interatrialpressure vent 100 is positioned in the correct orientation over theinner shaft 113 of the placement catheter 111 with the inner shaft 113oriented through the center of the flow control element 104. Fifth, theflange segments 102 a-h and 103 a-h are folded away from each other andthe flange segments 102 a-h and 103 a-h and the core segment 106 arecompressed radially to fold the interatrial pressure vent 100 into asize and shape that will fit over and onto the waist section 120 of theinner shaft 112 with the distal ends 115 of flange segments 102 a-haligning with the proximal groove 114 of inner shaft 112.

In embodiments comprising a flange as described in FIG. 11A the flangesegments 102 a-h and 103 a-h are folded away from each other and theflange segments 102 a-h and 103 a-h and the core segment 106 arecompressed radially to fold the interatrial pressure vent 100 into asize and shape that will fit over the flange 3000 described on FIG. 11A.This folding may be accomplished with the aid of an insertion tool (notshown) that retains the interatrial pressure vent 100 in a stowedposition on inner shaft 112 and then advancing outer shaft 113 over thestowed interatrial pressure vent 100 and displacing the insertion tool,thereby leaving the outer shaft 113 completely covering the interatrialpressure vent 100 and mating with the distal tapered tip 140 of theinner shaft 112. In other embodiments, this can be accomplished by handusing the fingers of one hand to hold the distal ends 115 of the flangesegments 102 a-102 h in position at groove 114 of the inner shaft 112and advancing the outer shaft 113 over the inner shaft 112 enough tohold the flange segments 102 a-102 h in place. Completion of the loadingprocedure is accomplished by progressively advancing the outer shaft 113until it completely covers the interatrial pressure vent 100 as shown inFIGS. 11 and 11A. While the below discussion regarding placement of theinteratrial pressure vent uses the placement device shown in FIGS. 9-11as an example, the description on placement and the procedure thereforeis also meant to apply to embodiments where the inner shaft comprises aflange rather than grooves.

Positioning of the loaded interatrial valve 100 and placement catheter111 in preparation for implanting the interatrial valve 100 in thepatient can be accomplished by: first gaining vascular access; second,positioning a guidewire 121 in the right atrium of the patient; third,positioning an introducer (not shown) into the patients right atrium;fourth, locating the interatrial septum; fifth, advancing the introducerthrough the interatrial septum and into the patient's left atrium;sixth, advancing the guidewire 138 into the left atrium; seventh,retracting the introducer; eighth, advancing the loaded placementcatheter 111 and interatrial pressure vent 100 into position so thedistal end and approximately half of the stowed length of theinteratrial pressure vent 100 is protruding through the interatrialseptum and into the patient's left atrium as shown in FIG. 13 .

In embodiments, positioning of the loaded interatrial valve 100 andplacement catheter 111 in preparation for implanting the interatrialvalve 100 in the patient can be accomplished by: first gaining vascularaccess; second, positioning a guidewire 138 in the right atrium of thepatient; third, advancing the loaded interatrial valve 100 and placementcatheter 111 over guidewire 138 by inserting the guidewire into andthrough lumen 136 and advancing placement catheter 111 into thepatient's right atrium; fourth, locating the interatrial septum; fifth,advancing the placement catheter 111 through the interatrial septum andinto the patient's left atrium so the distal end and approximately halfof the stowed length of the interatrial pressure vent 100 is protrudingthrough the interatrial septum and into the patient's left atrium asshown in FIG. 13 .

Implanting interatrial pressure vent 100 into a patient can beaccomplished, once the loaded interatrial pressure vent 100 andplacement catheter 111 are in position as shown in FIG. 14 , by first,retracting first handle component 128 toward second handle component 129while holding second handle component 129 until flange segments 103 a-hare fully uncovered as shown in FIG. 15 , and as can be verified byvisualizing the markers 119 using fluoroscopy or using echocardiography;second, retracting the placement catheter 111 with partially deployedinteratrial pressure vent 100 toward the patient's right atrium untilthe flange segments 103 a-h are in contact with the left atrial side ofthe interatrial septum, as shown in FIG. 16 , and as can be verifiedusing the same techniques mentioned or as can be perceived by the userbased on the resistance felt against further proximal movement of theplacement catheter 111; fourth, continuing to retract the outer sheath113 by retracting second handle 129 until the outer sheath 113 isretracted beyond the proximal end of groove 114 of inner shaft 112 andalso uncovers flange segments 102 a-h, at which time the flange segments102 a-h of interatrial pressure vent 100 will deploy returning to thepreloaded geometry and capture the interatrial septum between the flangesegments 103 a-h and flange segments 102 a-h as shown in shown in FIG.18 ; fifth, the inner sheath is retracted through the flow controlelement 104 of interatrial pressure vent 100, into the patients rightatrium as shown in FIG. 19 ; fifth the second handle component 129 isadvanced toward the first handle component 128 to reposition inner shaft112 into the position relative to outer shaft 113 it was in duringplacement and the placement catheter is removed from the patient and theprocedure is completed.

In other embodiments, implanting interatrial pressure vent 100 into apatient can be accomplished, once the loaded interatrial pressure vent100 and placement catheter 111 are in position as shown in FIG. 14 , byfirst, advancing second handle component 129 toward first handlecomponent 130 while holding first handle component 128 until flangesegments 103 a-h are fully uncovered as shown in FIG. 15 , and as can beverified by visualizing the markers 119 using fluoroscopy or usingechocardiography; second, retracting the placement catheter 111 withpartially deployed interatrial pressure vent 100 toward the patient'sright atrium until the flange segments 103 a-h are in contact with theleft atrial side of the interatrial septum, as shown in FIG. 16 , and ascan be verified using the same techniques mentioned or as can beperceived by the user based on the resistance felt against furtherproximal movement of the placement catheter 111; fourth, continuing toretract the outer sheath 113 by retracting second handle 129 until theouter sheath 113 is retracted beyond the proximal end of groove 114 ofinner shaft 112 and also uncovers flange segments 102 a-h, at which timethe flange segments 102 a-h of interatrial pressure vent 100 will deployreturning to the preloaded geometry and capture the interatrial septumbetween the flange segments 103 a-h and flange segments 102 a-h as shownin shown in FIG. 18 ; fifth, the inner sheath is retracted through theflow control element 104 of interatrial pressure vent 100, into thepatients right atrium as shown in FIG. 19 ; fifth the second handlecomponent 129 is advanced toward the first handle component 128 toreposition inner shaft 112 into the position relative to outer shaft 113it was in during placement and the placement catheter is removed fromthe patient and the procedure is completed.

For a variety of reasons, it may be necessary or desirable to removeinteratrial pressure vent 100 and placement catheter 111 during any partof the procedure without further risk or injury to the patient. This ispossible as follows: if, for any reason, it is desired for the device tobe removed before outer shaft 113 is retracted and flange segments 103a-h are deployed, then the placement catheter 111 with interatrial valve100 can simply be retracted out through the same pathway as introduced.

If, following deployment of flange segments 103 a-h it is necessary ordesirable to remove the device, then the interatrial valve 100 can beretracted into the placement catheter 111 by advancing first handle 128away from second handle 129, while holding second handle 129 stationary,thereby advancing outer sheath 113 distally through the interatrialseptum and over the flange segments 103 a-h. In embodiments, radiopaquemarkers 118 placed in marker holes 109 are captured in groove 114 (seeFIG. 17 ) and cannot fit in the gap between waist 120 of inner shaft 112and inner surface of outer shaft 113, so as outer sheath 113 isadvanced, flange segments 103 a-h are forced to fold inward toward theirstowed position and are retracted back onto inner shaft 112 and withinouter sheath 113. Once outer shaft 113 is fully advanced, catheter 111can be retracted as shown in FIG. 17 to be removed out through theinteratrial septum and out through the same pathway as introduced.

FIG. 19B is an embodiment designed to enhance the retrievability of thedevice. The procedure for implanting the device is substantially similarto that which is described above; however, there are variations to theplacement catheter and the device, which will be described below. Asdiscussed in connection with FIGS. 7A through 7C, embodiments of theinteratrial venting device comprise at least one flange segment beinglonger than the other flange segments. The embodiment schematicallyshown in FIG. 19B preferably works with such embodiments having at leastone flange segment that are longer in relation to the other flangesegments; thus the segments shown in the RA have the same referencenumber as the longer segments in FIGS. 7A through 7C, i.e., 102L. Inembodiments utilizing the techniques shown in FIG. 19A, the opening 113a of outer sheath 113 of placement catheter is angled or has a moresurface area on one side relative to the other. The placement catheteris oriented during the procedure such that the angled opening (or theplane of the opening itself) is at an angle more normal to the septalwall 107. In the embodiment shown in FIG. 19B, that angle appears to bearound 45 degrees with respect to the septal wall 107, but any anglewhich provides an more normal angle with respect to the septal wall maybe used, and any opening which provides more surface area of the outersheath 113 on one side with respect to the other side may be used.Reference numerals 4000 through 4050 refer to steps in the processdescribed below. The process is largely similar to that described aboveor with respect to any well-known placement catheter system and process,therefore only the applicable differences will be described. As can beseen at steps 4000 through 4020, the placement catheter is positionedand the device is in the beginning stages of deployment. At steps 4030and 4040, the as the outer sheath 113 is retracted and on the RA side(or when the inner shaft is advanced while the outer sheath is on the RAside, which is not shown), the opening allows one of the longer flangesegments 102L, to be deployed after other flange segments have beendeployed and are thus in contact with the septum 107. The at least onelonger flange segment 102L is retained in the placement catheter systemby way of the outer sheath 113, the length of which extends further onone side than the other due to the opening and thus covers the longersegment 102L while the other shorter segments have been deployed. Inthis way, the operator of the placement catheter can determine if theinteratrial device is in the proper position. If not, the operator canstill retrieve the device up until the last point prior to fulldeployment, i.e., when at least one of the longer flange segments (102Lfor example) is still retained in the placement catheter by the outersheath 113. If it is in proper position, the deployment may commence.

Another deployment embodiment is now described in connection with FIG.19C. This deployment embodiment may be used with any embodiment of theinteratrial vent described herein. Reference numerals 5000 through 5050refer to steps in the process described below. At step 5000, the LA sideof the device (generally referred to in this figure as 100) is deployedon the LA side of the heart. Further deployment is shown at step 5010and the outer sheath is retracted into the RA side of the heart, whichallows flow control element 104 to exit the placement catheter.Placement catheter is equipped with a balloon, which is in fluidcommunication, for example, with lumen 136 described above or guide wire138. The skilled artisan will appreciate other configurations in which aballoon catheter may be provided in the placement catheter system. Upondeployment of the LA side flange or shortly thereafter, balloon 139 isinflated (shown in step 5020). The inflation of the balloon optionallycoupled with a pulling-back motion of the placement catheter 111 holdsthe device 100 against the LA side of the septal wall 107 and therebyprevents the device 100 from dislodging during deployment and/or movingin a direction away from the septal wall. Step 5040 shows the fulldeployment of the device 100 while the balloon 139 is inflated. Whensatisfactory deployment is achieved, the balloon 139 is deflated and theplacement catheter system is removed (shown at step 5050).

Now referring to FIG. 20 , an interatrial pressure vent 200 is shown. Inembodiments, flange segments 202 a-h and 203 a-h can be formed withgraduating length to reduce interference between flange segments 202 a-hand 203 a-h during handling, folding and loading. In embodiments,radiopaque markers 218 and 219 protrude into the inner cylindrical shapeof the stowed position of the interatrial pressure vent and each flangesegment 202 a-h and 203 a-h differ in length by at least the width ofthe radiopaque markers 218 and 219. In embodiments, each flange segment202 a-h and 203 a-h differ in length by at least at least 1 mm. Inembodiments, each flange segment 202 a-h and 203 a-h differ in length byat least 2% of the overall length of interatrial pressure vent 200 inthe position shown in FIG. 20 .

Now referring to FIG. 21 , an interatrial pressure vent 300 is shown. Inembodiments, flange segments 302 a-h and 303 a-h can be formed withalternating length to reduce interference between flange segments 202a-h and 203 a-h during handling, folding and loading. In embodimentsradiopaque markers 318 and 319 protrude into the inner cylindrical shapeof the stowed position of the interatrial pressure vent 300 andalternating flange segments 302 a, c, e, and g are longer than flangesegments 302 b, d, f and h, and correspondingly, flange segments 303 b,d, f and h are longer than flange segments 303 a, c, e and g by at leastthe width of the radiopaque marker. In embodiments, alternating flangesegments 302 a, c, e and g are longer than flange segments 302 b, d, fand h and, correspondingly, flange segments 303 b, d, f and h are longerthan flange segments 303 a, c, e and g by at least 1 mm. In one aspectthe alternating flange segments 302 a, c, e and g are longer than flangesegments 302 b, d, f and h and, correspondingly, flange segments 303 b,d, f and g are longer than flange segments 303 a, c, e and g by at least2% of the overall length of interatrial pressure vent 300 in theposition shown in FIG. 21 .

Referring now to FIG. 22 and FIG. 23 , the body element 401 of aninteratrial pressure vent with integral thrombus filter and retrievalcone 442 is shown. In embodiments, conical struts 444 are affixed tobody element 401 at attachment points 446 and converge at apex 450. Inembodiments, conical struts 444 comprise single beams of similarmaterial to flange segments 402 and 403 and can be attached to the bodyelement or formed at the same time as the body element using techniquesdescribed in this specification, and are thus integral with theremainder of the device. In embodiments the space between adjacentstruts 444 is about 2 mm. In embodiments, the space between adjacentstruts 444 is about 4 mm. As can be appreciated, conical struts 444 willprotrude into the right atrium of the patient after implant and spacesbetween conical struts will function to block the passage of solidmaterial larger than the space between adjacent struts 444. This willprovide the function of preventing emboli that are larger than the spacebetween the adjacent struts 444 from passing from the right atrium tothe left atrium.

Referring again to FIG. 22 and FIG. 23 , in embodiments the shape of theconical struts 444 is not straight. In embodiments the shape of theconical struts 444 can be concave when viewed on end as depicted in FIG.22 . In embodiments the conical struts can be curved in a direction awayfrom the chord formed between the apex 450 and the attachment points446. In embodiments there can be a hole 451 through apex 450 largeenough to receive a retrieval snare (not shown). It can be appreciatedthat conical struts 444 and apex 450 can be used to aid retrieval of theinteratrial pressure vent from a patient at some time after the implantprocedure using a method as follows: A catheter tube with an internallumen at least as large as apex 450 can be placed into the patientsright atrium using standard techniques and imaging equipment. Aretrieval snare can be fabricated from the proximal end of a guidewirebent sharply by about 180 degrees and this snare can be inserted throughthe catheter tube and advanced into the patient's right atrium and withthe assistance of fluoroscopy advanced through hole 451 or aroundconical struts 444. Once the retrieval snare is engaged in this manner,it will be possible to retract the interatrial pressure vent byadvancing a catheter tube while holding slight tension on the snare andthereby guide the catheter tube over apex 450 and onto conical struts444.

As the catheter tube continues to advance, with some tension on thesnare it will be possible to force the conical struts inward, therebyforcing the flange segments 402 to begin folding inwards. When theconical struts are nearly completely in the catheter tube, the cathetertube can be held in a stationary position and the snare wire retractedagainst it, thereby causing the attachment points 446 between theconical struts 444 and the flange segment 402 to be retracted into thecatheter. Flange segments 402 can begin to be retracted into thecatheter at this point and the distal ends of flange segments 402 can bediverted toward the patients left atrium but will also fold inward andinto the catheter. Once the flange segments 402 are inside of thecatheter tube, the snare can be held stationary and the catheter tubecan be advanced further, through the interatrial septum and over flangesegments 403. Once the flange segments 403 are retracted into thecatheter, the catheter and snare can be moved together to retract theinteratrial pressure vent into the patient's right atrium and outthrough the pathway through which it was introduced.

Referring now to FIGS. 24 and 25 an alternate embodiment of interatrialpressure vent 500 is shown. In embodiments, flow control element 504 iscomprised of leaflets 541 a-c. Body element 501 is comprised of coresegment 506 and flange segments 502 a-l and 503 a-l (not fully visiblein FIG. 25 ); the number of flange segments being a multiple of thenumber of leaflets. This configuration improves the symmetry of strainagainst the flow control leaflets and also improves the uniformity ofmotion by the flow control element to changes in blood flow.

In embodiments the number of leaflets comprising the flow controlelement is three and the number of flange segments on each side of thecore segment is twelve. In embodiments, the number of leafletscomprising the flow control element is three and the number of flangesegments on each side of the core segment is nine. In embodiments, thenumber of leaflets comprising the flow control element is three and thenumber of flange segments on each side is six.

In embodiments, the number of leaflets comprising the flow controlelement is three and the number of flange segments on each side isthree. In embodiments, the number of leaflets comprising the flowcontrol element is three, the number of flange segments on one side ofthe core segment is twelve and the number of flange segments on theother side of the core segment is nine. In embodiments, the number ofleaflets comprising the flow control element is three, the number offlange segments on one side of the core segment is twelve and the numberof flange segments on the other side of the core segment is six.

In embodiments, the number of leaflets comprising the flow controlelement is three, the number of flange segments on one side of the coresegment is twelve and the number of flange segments on the other side ofthe core segment is three. In embodiments, the number of leafletscomprising the flow control element is three, the number of flangesegments on one side of the core segment is nine and the number offlange segments on the other side of the core segment is six. Inembodiments, the number of leaflets comprising the flow control elementis three, the number of flange segments on one side of the core segmentis nine and the number of flange segments on the other side of the coresegment is three.

In embodiments, the number of leaflets comprising the flow controlelement is three, the number of flange segments on one side of the coresegment is six and the number of flange segments on the other side ofthe core segment is three. In embodiments, the number of leafletscomprising the flow control element is two and the number of flangesegments on each side of the core segment is twelve. In embodiments, thenumber of leaflets comprising the flow control element is two and thenumber of flange segments on each side of the core segment is ten. Inembodiments, the number of leaflets comprising the flow control elementis two and the number of flange segments on each side of the coresegment is eight.

In embodiments, the number of leaflets comprising the flow controlelement is two and the number of flange segments on each side of thecore segment is six. In embodiments, the number of leaflets comprisingthe flow control element is two and the number of flange segments oneach side of the core segment is four. In embodiments, the number ofleaflets comprising the flow control element is two and the number offlange segments on each side of the core segment is two.

In embodiments, the number of leaflets comprising the flow controlelement is two, the number of flange segments on one side of the coresegment is twelve and the number of flange segments on the other side ofthe core segment is ten. In embodiments, the number of leafletscomprising the flow control element is two, the number of flangesegments on one side of the core segment is twelve and the number offlange segments on the other side of the core segment is eight. Inembodiments, the number of leaflets comprising the flow control elementis two, the number of flange segments on one side of the core segment istwelve and the number of flange segments on the other side of the coresegment is six.

In embodiments, the number of leaflets comprising the flow controlelement is two, the number of flange segments on one side of the coresegment is twelve and the number of flange segments on the other side ofthe core segment is four. In embodiments, the number of leafletscomprising the flow control element is two, the number of flangesegments on one side of the core segment is twelve and the number offlange segments on the other side of the core segment is two. Inembodiments, the number of leaflets comprising the flow control elementis two, the number of flange segments on one side of the core segment isten and the number of flange segments on the other side of the coresegment is eight.

In embodiments, the number of leaflets comprising the flow controlelement is two, the number of flange segments on one side of the coresegment is ten and the number of flange segments on the other side ofthe core segment is six. In embodiments, the number of leafletscomprising the flow control element is two, the number of flangesegments on one side of the core segment is ten and the number of flangesegments on the other side of the core segment is four. In embodiments,the number of leaflets comprising the flow control element is two, thenumber of flange segments on one side of the core segment is ten and thenumber of flange segments on the other side of the core segment is two.

In embodiments, the number of leaflets comprising the flow controlelement is two, the number of flange segments on one side of the coresegment is ten and the number of flange segments on the other side ofthe core segment is two. In embodiments, the number of leafletscomprising the flow control element is two, the number of flangesegments on one side of the core segment is eight and the number offlange segments on the other side of the core segment is six. Inembodiments, the number of leaflets comprising the flow control elementis two, the number of flange segments on one side of the core segment iseight and the number of flange segments on the other side of the coresegment is four.

In embodiments, the number of leaflets comprising the flow controlelement is two, the number of flange segments on one side of the coresegment is eight and the number of flange segments on the other side ofthe core segment is two. In embodiments, the number of leafletscomprising the flow control element is two, the number of flangesegments on one side of the core segment is six and the number of flangesegments on the other side of the core segment is four. In embodiments,the number of leaflets comprising the flow control element is two, thenumber of flange segments on one side of the core segment is six and thenumber of flange segments on the other side of the core segment is two.

In embodiments, the number of leaflets comprising the flow controlelement is two, the number of flange segments on one side of the coresegment is four and the number of flange segments on the other side ofthe core segment is two.

FIG. 26 shows and alternate embodiment wherein the core segment 106 isovular rather than circular and thus the core segment is a cylindroid orelliptic cylinder rather than a simple cylinder. This embodiment is moreconducive to a bicuspid (or “duckbill”, bivalve, or two-leaflet)configuration for the flow control element. The duckbill configurationis generally referred to as flow control element 104 in this figure. Theinventors have found that the bi-valve configuration is able to openmore fully when coupled with a core segment in the shape of acylindroid.

FIGS. 27 and 27A show another embodiment of an interatrial device havingintermediate flange segments for a more secured fit against the septalwall. In embodiments, the intermediate flange segments are part ofanother a third annular flange situated on the same side of the septalwall as one of the other flanges. Reference numerals 6000 through 6040refer to steps in the deployment of such an embodiment and will bediscussed in connection with the structural features of the embodimentto illustrate this embodiment's utility and operation. The deploymentprocess is similar to those described above, and to any commonly-knowncatheter based delivery process and as such the details of the processwill not be discussed herein. Steps 6000 to 6020 show the deploymentprocess steps proceeding in much the same manner as described herein. Atstep 6030, intermediate flange segments 602 and 604 of intermediate (orthird) annular flange are deployed on the RA side. In this embodiment,intermediate flange segments 602 and 604 are shorter than the majorityof the flange segments of the RA-side flange. As such, segments 602 and604 are deployed prior to other longer segments and contact the septalwall 107 at points closer to the septal opening than the contact pointsof the longer segments. In this manner, the intermediate segments 602and 604 (and the flange which they comprise) provide increased stabilityof the device. Any number of intermediate segments may be used althoughit is preferable to have at least two. As with other embodiments, thestiffness of the intermediate segments may be altered so as to differfrom other flange segments of the device to avoid damage to the septalwall, i.e., lesser stiffness/greater flexibility, or to provideincreased stability, i.e., greater stiffness/lesser flexibility. Thechoice of stiffness/flexibility variations must be balanced against thedesired goals.

FIG. 27A is a side elevational view of embodiment discussed inconnection with FIG. 27 . In FIG. 27A the pressure venting device in itsstowed configuration. Flanges 102 and 103 are shown with the flangesegments that comprise them (flange segments not individually labeled).Core segment is again shown as 106. At a point between the end of thecore segment 106 and proximal end of the RA side flange segment 102, theintermediate segments (collectively referred to as 600) emerge.Intermediate segments may be integral with the venting device orattached thereto in the manners described above.

In other embodiments, the flow control element is configured to directthe blood flow in a desired direction. FIGS. 28A through 28C show suchembodiments. In FIG. 28A interatrial device 100 is shown implanted inthe atrial septum 107 of the heart in the same manner as shown in FIG. 1. Flow control element 104 is configured to aim the, shown in thisfigure as in the direction toward the superior vena cava. FIGS. 28B and28C show a more detailed view of embodiments that enable the flow to bedirected in a desired direction. As shown in FIG. 28B, flow controlelement comprises a baffle-like flange 104 a that extends at a downwardangle and in the corresponding direction. In use, such embodimentdirects the flow downward. FIG. 28C shows an embodiment where the flowis directed upward. The valve material (e.g. material for leaflets) canbe sized and secured to the 100 in manner to direct the flow. Forexample, the flow control element may contain a curved tubular memberwhose opening points toward the direction of flow, or the flow controlelement may otherwise comprise an opening directed at the area ofinterest. In embodiments with baffles, the stiffness of the baffle 104 amay be varied, for example, made stiffer. The length of the baffle canalso be varied depending on the desired flow direction. The baffle canbe a separate member attached to the flow control element or it may bemade of the material and/or integral with the remainder of the flowcontrol element.

FIGS. 29A through C show exit profile shapes of the flow control element104. In these figures, the flow control element 104 is being viewed fromthe RA side and thus the direction of flow is understood to coming outof the page at an angle substantially normal to the page. If the flowcontrol element is a valve as described herein, folding and suturingpatterns may be employed to achieved these exit profile shapes. In otherembodiments, the end of the flow control element may be provided with aplate, or a partially frustoconical end piece, having an openingdefining the two-dimensional shape shown in the Figure. The skilledartisan will appreciate that other exit profile shapes may be fashioned.The selection of an exit profile shape may provide advantages such asdirecting flow, preventing thrombi from moving across the septal divide,and/or reducing injury to surrounding tissue.

Another embodiment is shown in FIG. 30 . In this embodiment, the coresegment 106 and flanges 102 and 103 of the device are substantiallysimilar those described herein. Instead of the flow control elementsdescribed above (or in addition thereto) a tube-like member 700 issecured to the core segment 106. The tube member 700 is attached to thecore segment 700 in a manner to allow the RA end of tube to extend intothe RA in an axial direction, thus the tube's length must be sufficientto extend a distance into the RA. It has been found that the tube 700configured in this manner prevents embolic particles from entering thetube and crossing over the septal divide into the LA. The distance thatthe tube 700 extends into the RA and beyond the plane of the RA-sideflange opening (indicated by dotted line) should be at least a 1 mm butmay be up to 2 cm in preferable embodiments. Even at relatively shortlengths (such as where the tube extends only a few millimeters into theRA), the inventors have noted the surprisingly unexpected result of areduction of embolic particles passing through. This is due to, in part,the tendency of embolic particles to collect along the surface of theseptal wall and move toward the septal opening (or opening of animplanted device) with each cycle of the heart. By extending away fromthe septal wall 107, the tube provides an effective barrier to theembolic particles that would otherwise travel toward and possiblythrough the septal opening.

Placing the Interatrial Pressure Vent or Prosthesis into a Mounting Tool

FIG. 31 depicts a first embodiment of a mounting and loading tool usefulfor placing the prosthesis onto a catheter or other delivery device fordelivery in vivo to a patient. In this embodiment, mounting tool 2001includes a base plate 2002 with orifices 2003 for securing othercomponents as shown with fasteners 2004 and pin 2009. The principalcomponent is a loader body 2014, mounted via the outer two fasteners andorifices as shown. A mounting platform 2023 is mounted in the center ofthe loader body via the third orifice and pin 2009. Mounting platform2023 includes a lower orifice 2026 for mounting to the loader body viathe middle loader body orifice with pin 2009. Mounting platform 2023also includes a slotted cam surface 2024. Pivot 2029 mounts to theloader body 2014 via pivot pin 2028 through pivot orifice 2030 andloader body orifice 2016. Pivot 2029 and lever 2031 mount on the leftside of loader body 2014 below the side doors 2020, as seen in FIG. 31 .Movement of pivot 2029 and lever 2031 on the cam surface allows a userto raise and lower the mounting platform. The two opposite positions ofthe mounting platform are the lower and upper positions, achieved byrotating the pivot to the desired position. In other embodiments, thecam surface may simply be a slot or groove in the side of the mountingplatform 2023.

The loader body 2014 also mounts the other components of the device. Theloader body includes internal side channels 2018 for mounting two sidedoors 2020 and also includes vertical bores 2015 and a vertical sidechannel 2019 for mounting top plate 2005. The side doors 2020 include acentral orifice 2027 in the shape of a semicircle, for closing againstthe prosthesis, discussed below. The side doors include shelves 2021 oneither side for riding against the channel 2018 of the loader body. Theside doors each also include a retaining pin 2022. The pins protrudethrough side windows 2017 in the loader body and allow the side doors toslide within the loader body while preventing their complete removalfrom the assembly.

Top plate 2005 includes a top surface 2006, an adjustable internal iris2011, which functions much like the iris in a camera. The iris hassections that adjust inward and outward to open and to close the centralopening of the iris. The adjustable iris decreases the area of theopening and closes in a manner that allows the top section of theimplantable device to rest on top of the partially or full closed iris.Opening and closing of the iris is controlled by control lever 2013. Thetop plate includes two vertical rods 2007 for mounting in the verticalbores 2015 of the loader body and also includes a vertical side guide2008 with an elevating mechanism 2010 actuated by a top thumbwheel 2012.Raising and lowering via the elevating mechanism allows the user toraise and lower the iris and thus adjust the separation of the left andright flanges of the prosthesis with the iris.

The mounting and loading assembly is used in the following manner. Theloader body is positioned conveniently for the user, with the top plateremoved and with the doors open. A prosthesis, such as prosthesis 100,is placed on the loading platform, with the left atrium legs or flangefacing downward and with the loading platform in the lower position. Thedoors 2020 are then closed, with the mounting platform still in thelower position, thus placing the left atrium flange below the doors. Themounting platform 2023 is then raised to its upper position by rotatingpivot 2029, causing the lower portion (left atrium flange or legs) to bepressed against the under side of the doors 2020. While not shown inFIG. 31 , this movement causes the legs of the left atrium flange to beradially spread out.

At this point, the top plate is assembled to the mounting and loadingtool and a catheter, such as one of the catheters depicted above inFIGS. 10-12 , and also described above, is introduced though the centerof the prosthesis. The portion inserted includes the catheter tip and aportion of the catheter control wire connected to the tip. The positionof the catheter is adjusted so that the right atrium ball (“RA ball”) orother retention device is vertically aligned with the right atriumflange, as discussed above with respect to FIG. 11A. The iris is thenpartially closed. Vertical alignment may be achieved by raising the topplate 2005 using handwheel 2012. With the doors 2020 closed and the leftatrium flange trapped below the doors, raising the top plate willstretch the prosthesis, separate the left and right atrium flanges, andalso stretch the prosthesis over the catheter. In one embodiment, thediameter of the orifice made by the two half-circular cut outs 2027 ofthe side doors is about equal, or slightly less than, a diameter of thecatheter intended for use as a delivery device for the prosthesisdiscussed herein. The diameter may range from about 3 mm (9 Fr) to about7 mm (21 Fr).

As the iris is raised, the upper (right atrium) flange will approach theretention device, such as the RA ball and the outer sheath of thecatheter. The iris may continue to be closed while the top plate israised, thus bringing the RA flange into contact with the RA ball. Ifthe mounting platform 2023 has not been fully raised, it may also beraised gradually during this process. The entire sequence may beachieved by sequential use of the mounting platform 2023 and pivot 2029,the iris 2011 and handle 2013, and the elevating mechanism 2010 andthumbwheel 2012. When the RA flange has closed over the RA ball, theouter sheath may then be brought over the RA flange, securing the end ofthe prosthesis in the outer sheath. At this point, the iris 2011 may beopened along with doors 2020 and the catheter and prosthesis removedfrom the mounting and loading tool. The inner wire, firmly attached tothe catheter tip and RA ball, is then retracted, pulling the centralportion of the prosthesis and the LA flange into the outer catheter.

The catheter is then processed as discussed above, including assembly toa control device or handle, packaging, and so forth. This process isdesirably performed in a sterile environment, with all components,tools, fasteners, and so forth, scrupulously clean and sterile beforeand during all steps of the process. The mounting and loading tooldepicted in FIG. 31 and described above is desirably made from an inert,lubricious and medically-acceptable plastic material, such as afluoropolymer, fluorinated ethylene-propylene, PTFE, UHMWPE, acetal,polycarbonate, and so forth.

In addition to the mounting and loading tool discussed with respect toFIG. 31 , there are other embodiments for mounting a prosthesis and forloading a prosthesis onto a catheter or delivery device. Additionalembodiments of useful tools are discussed below. In the discussionbelow, FIGS. 32-34 concern a discrete mounting tool, while FIG. 35concerns a separate tool for loading a mounted prosthesis onto a loadingtool.

FIG. 32 depicts a mounting tool 2500 useful for mounting a prosthesisfor relieving intracardial pressure for a mammal, such as a human. Themounting tool includes four principal components. The principalcomponents include a mounting plate 2501, a star-shaped cutout plate2511, a lower flat disc 2521, also known as a right atrium or RA disc,and an upper counterbored disc 2531, also known as a left atrium or LAdisc. The four components are used and stacked in the manner depicted inthe drawing, in combination with a prosthesis mounted on the tool. Allfour components are desirably made from a lubricious, non-allergenic,medically-acceptable plastic, such as a fluoropolymer, fluorinatedethylene-propylene, PTFE, UHMWPE, acetal, polycarbonate, and so forth.

Mounting tool 2500 includes mounting plate 2501 having a cylindricalbottom disc 2503, the disc having a central raised portion 2505 and anadditional raised portion 2507 atop the central raised portion. Plate2501 also includes a plurality of inserts 2502 for attracting andjoining with a similar number of inserts in cutout plate 2511. Theinserts may be magnets or a combination of magnets andmagnetically-attractive materials.

Star-shaped cutout plate 2511 includes a flat top surface 2512 with acutout in a general shape of a star 2515. While the cutout has thegeneral shape of a star, it is understood that the shape need not be aperfect star with perfectly equal sides and perfect angles between alllegs or sides of the star. For example, the tips and corners of eachpoint of the star are rounded rather than sharp. This avoids scratchingthe prosthesis and also avoids any scratching of personnel assemblingthe prosthesis to a catheter. A cutout in a general shape of a star issufficient to accomplish the task described herein. The skilled artisanwill appreciate that the shape would be appropriate for accommodatingthe shape of the device.

The bottom surface includes a counterbore 2514 for most of the entirebottom surface. A counterbored surface typically has an abrupt orright-angle termination, such as achieved by molding or by machiningwith an end-mill or other flat-bottomed tool. The counterbored surfaceis preferable to a more gradual change, such as a funnel-shapedcountersink or angled approach. As discussed below, the counterboredsurface of the cutout plate is used to mount the cutout plate to aloading tool. Thus, having the walls of the counterbore straight ratherthan angled is helpful, because with sufficiently close tolerances, thecounterbore aids in firmly securing the cutout plate to the loading toolused. It is possible, however, that angled walls, i.e., a countersink,may be used instead. Cutout plate 2511 also includes a plurality ofinserts 2502 matching the plurality of inserts in mounting plate 2501.In one embodiment, the inserts are polar magnets, i.e., N-S magnets withthe poles arranged so that the discs can only be joined in one way.

For example, mounting plate 2501 may have eight N-S magnets molded intothe plate with the north poles on the top side, with the raisedportions. If cutout plate 2511 has the magnets similarly mounted, northpoles on top, south poles on bottom, then the south poles on the bottomof cutout plate 2511 will attract the north poles on the top side ofmounting plate 2501, and the two plates may be joined. Because of thepolar orientation, there will be no magnetic attraction if one tries toassemble the discs in the incorrect manner, i.e., with the counterboredsurface on top. In another incorrect orientation, with the cutout plate2511 below mounting plate 2501, the plates will be magneticallyattracted for assembly, but the star-shaped feature 2515 will bepositioned away from the raised portions 2505, 2507. A user will not beable to position the prosthesis on the mounting tool using both theraised surfaces and the star-shaped cutout. Thus the mounting plate 2501and the cutout plate 2511 have been designed for assembly and forfool-proof assembly.

Right atrium disc or lower flat disc 2521 is made as a two-partassembly, a right half 2522 and a left half 2523. There is a centralorifice 2525 and the disc has a chamfer or bevel 2526 on its side. Eachside of each half has three bores 2527 within the disc and perpendicularto a radius of the disc, the three bores on each side used to assemblethe halves. In one embodiment, the outer two bores are used for magnetsto attract the halves together and the central bore is used for a dowelto align the halves. Thus, in one embodiment, right half 2522 has threebores 2527 as shown, the central bore being merely a void for acceptinga dowel from the left half, and the two side bores filled with twonorth-south magnets with the south poles facing outward. Left half 2523has three bores 2527 on each side, the central bore on each side filledwith a protruding dowel 2528 and the two side bores filled with twonorth-south magnets with the north poles facing outward. Use of thedowel and the void may be considered as a male-female joint. When thetwo halves are brought into contact, the opposite poles of the magnetswill attract and the two halves will be firmly joined.

The left atrium disc 2531, also known as the upper counterbored disc, isalso formed as two halves, right half 2532 and left half 2533.Counterbored disc 2531 has a counterbore 2534 on top, the counterboredor void portion removing material from a majority of the top surface.There is a chamfer or bevel 2536 on the side of the disc toward thebottom, such that when counterbored disc 2531 is assembled with lowerflat disc 2521, there is a “V” in profile, the “V” formed by the bevelsor chamfers on the two discs. Counterbored top disc 2531 also has acentral bore 2535 of about the same diameter as central bore 2525 oflower flat disc 2521. Each side of the halves includes three bores 2537within the disc, the bores perpendicular to a radius of the disc. Thebores are voids for accepting devices for joining the two halves, asdiscussed above for the lower flat disc. In one embodiment, the centralbores include a dowel and a void for aligning the two halves, while theouter bores include magnets 2502 with oppositely-facing poles forattracting each other. The dowel and void function for assembly as a taband a slot in both the right and left atrium discs 2521, 2531. The boresmay themselves be considered a slot, for use with a dowel, a tab, amagnet or a magnetic material. The tabs may be made of a plasticmaterial or may be made of durable stainless steel or othernon-corroding, medically-acceptable material.

In other embodiments for the side bores on either the lower plate 2521or the upper counterbored disc 2531, the inserts could include magnetson one half and steel or iron bars on the other half, or one magnet andone steel bar on each half, with a facing magnetically-attractive metaland magnet on the other half.

In one embodiment, the lower flat disc 2521 may be made a differentheight than the height of the upper counterbored disc 253L Thedifference in heights makes it unlikely that an improper assembly couldoccur between one half of the lower flat disc and one half of the uppercounterbored disc. In one embodiment, the magnets of the halves with thecentral dowels may be assembled with the north poles outward, while themagnets of the halves with the central voids may be assembled with thesouth poles outward. This would make mis-assembly of the lower flat disc2521 and the upper counterbored disc 2531 very difficult, since twopieces with dowels (male portions) would be impossible to join. Whilethe two pieces with voids may be magnetically attractive and may join toform a mis-assembly, there would only be one assembled disc, since thetwo halves with the dowels could not be joined. Thus, use of the magnetsand dowels makes assembly of the discs virtually error-proof.

Mounting tool 2500 is used to orient a prosthesis for placement in aloading tool, as discussed below. In practice, a prosthesis forplacement in a patient's heart is placed on the mounting plate 2501. Inone embodiment, a right atrium (RA) flange is placed on the centralportion 2505. The star-shaped cutout plate 2511 is placed atop themounting plate 2501, with the points of the star placed atop the flangejoints of the RA flange, thus locking the prosthesis in place with theoppositely-facing magnets. The left atrium (LA) flange and the barrel,or central portion of the prosthesis, now stand above the raisedportions 2505, 2507 of mounting plate 2501. The right atrium disc 2521is now joined to the assembly between the right atrium flange (lowerportion) of the prosthesis and the left atrium flange (upper portion) bybringing the two halves together, such that the bevel 2526 is on theupper side of the disc 2521.

The left atrium disc 2531 is then added to the assembly atop the rightatrium disc, also by bringing the two halves together. In this instance,bevel 2536 of the left atrium disc 2531 faces downward. The chamfers orbevels of the two discs are thus adjacent when the mounting tool 2500 isassembly correctly, the bevels together forming a “V” which will be usedlater by the loading tool, as discussed below. The mounting plate 2501and the star-shaped cutout plate 2511 may then be removed. When theprosthesis has been placed correctly on the mounting tool and themounting plate and cutout plate are removed, the left atrium flangeprotrudes from the left atrium disc and the right atrium flangeprotrudes from the right atrium disc, as seen in FIGS. 33-34 .

The mounting tool is depicted in FIG. 33 after it has been assembledwith a prosthesis 100. The mounting tool includes mounting plate 2501with cutout plate 2511 atop the mounting plate, and with right atriumdisc 2521 atop left atrium disc 2531. In this figure, prosthesis 100 ismounted with left atrium flange 103 visible on top. Note the counterbore 2534 visible in the left atrium disc 2531. This is theconfiguration immediately after the prosthesis has been mounted and theleft and right atrium discs have been inserted to separate the left andright atrium flanges. Note also that bevels 2526 and 2536 are adjacent,forming a V when seen from the side.

In FIG. 34 , the mounting and cutout plates have been removed and theassembly 2560 has been inverted, with right atrium disc 2521 atop leftatrium disc 2531 and with the right atrium flange 102 of the prosthesis100 on top. Note that the right atrium disc 2521 is flat and has nocounterbore on the side seen in this view.

Loading the Prosthesis into a Loading Tool

After the prosthesis has been mounted, a loading tool may be used toassemble the prosthesis and place it into a catheter or other deliverydevice. A loading tool useful in this process is depicted in FIG. 35 andis herein described.

Loading tool 2600 includes a base plate 2601, side door supports 2611and 2621, a central column 2641 and a travel subassembly 2650. The baseplate, side door supports and central column each mount to the baseplate via fasteners 2604, as shown. In one embodiment, the fasteners maymount through the bottom and the heads may reside in countersunk orcounterbored recesses in the bottom of the base plate. The base platealso includes a travel control mechanism or thumbwheel 2606, includingtravel screw 2607 and spacer 2608. In this embodiment, the travelcontrol mechanism 2606, and the thumbwheel travel adjuster are mountedwithin the base plate, and a portion of the handwheel protrudes througha side of the base plate. Rotating the thumbwheel allows one to advanceor retract travel screw 2607 and thus raise or lower travel subassembly2650.

Side doors 2631 are identical and reside on side door supports 2611,2621. Main doors 2660 are also substantially identical and reside ontravel subassembly 2650. In one embodiment, door supports 2611, 2621each include a top shelf 2613 for capturing a side door and allowing itto ride back forth, to and fro. In addition, door supports 2611, 2621also each contain a travel stop or pin 2615, 2625. The pin stands in agroove 2637 within the side door, the pin limiting travel of the door tothat allowed by the grooves, e.g., the half-way mark of the centralcolumn 2641 and its concentric top surface 2643, on the one side, andretreat from the central column in the opposite direction whenappropriate. In this manner, the side doors can slide back and forthsymmetrically to meet each other. The side doors have a taper 2633 ontheir front, as well as a half-circular cutout 2635 on the from. Eachside door 2631 also has a vertical pin 2636 for ease of moving the doorback and forth and also limiting the forward travel, when the pintouches the shelf 2613. In one embodiment, the diameter of the orificemade by the two half-circular cut outs is about equal, or slightly lessthan, a diameter of a catheter intended for use as a delivery device forthe prosthesis discussed herein. The diameter may range from about 3 mm(9 Fr) to about 20 mm (60 Fr).

Main doors 2660 mount atop the travel subassembly 2650 via main doormounts 2651, 2652. The main doors slide back and forth in a mannerorthogonal to the side doors. In this embodiment, the main doors aresomewhat larger than the side doors and are used to compress theprosthesis to a diameter suitable for a catheter with a similarlydesirably small diameter for delivery to a patient. The front portion ofthe each of the main doors thus includes a transition 2664 to a frontalsemicircular arc 2665 and a semicircular bore 2666 with a radiusconsistent with such a small diameter. In one embodiment, the desireddiameter is about 3.3 mm or 10 Fr, and the radius of the front bore isthus about 1.65 mm. In other embodiments, the radius is from about 1 mmto about 4.5 mm, to accommodate delivery catheters from about 2 mm toabout 9 mm, and for catheters with a similar diameter.

The travel subassembly 2650 mounts to the loading tool via an internalthreaded bore 2657 that interfaces with threaded screw 2607. Movement ofthe thumbwheel 2606 moves travel subassembly 2650 up and down asdesired. Travel assembly 2650 includes door mounts 2651, 2652 includingtongues 2654 atop the mounts and pins 2653 for limiting travel of themain doors. The main doors 2660 are substantially identical and includea groove 2661 along their length of their bottom. Tongues 2653 ridewithin grooves 2661 of the main doors.

The main doors also include locking pins 2663. Each pin may be used tolock the main door 2660 into the closed position by closing the doorfully and depressing the pin to engage orifice 2655 in door mounts 2651,2652. The pins 2663 may also be used to restrain each door away from theclosed position by opening the main doors and depressing the pinsoutside travel subassembly 2650 so that further inward travel is notpossible with the pins depressed. Central column 2641 with mountingsurface 2643 mounts to the base plate 2601 via a central orifice 2645and a fastener from below the base plate. The central column ispositioned symmetrically within orifice 2656 of the travel subassembly2650. The central column and the mounting surface are stationary, whilearound them the travel subassembly 2650 travels vertically and sidedoors 2631 and main doors 2660 move horizontally.

Loading the Prosthesis into the Catheter

The loading tool is used in the following manner, in one embodiment.Other embodiments and other methods may also be used.

The side doors and main doors are opened to their full open positionsand the mounted prosthesis assembly 2560 described above is placed ontocentral column top surface 2643, with the right atrium flange or legs upand the left atrium flange down. Note that in this configuration, theleft atrium disc 2531, which is the disc with the large counterbore2534, faces downward. In one embodiment, the counterbore is sized andoriented to fit precisely onto top mounting surface 2643 of the loadingtool 2600, discussed below. Top surface 2643 is the mounting or loadingsurface for placing the mounted assembly 2560 into the loading tool2600.

Once the mounted assembly 2560 is placed into the loading tool 2600, thetravel subassembly 2650 is raised or lowered so that the side doorsalign with the “V” formed by the bevels or “V” of the mounted assembly.The side doors 2631 are then closed, bringing the tapered front portionsof the side doors into contact with the “V” and urging apart the leftatrium and right atrium discs of the mounting tool. The main doors 2660are then closed against the side doors 2631.

Once this has been accomplished, a delivery catheter 2040 is assembledto the prosthesis, as depicted in FIG. 36 . A clear loading tube 2561 ismoved over the outer sheath 2563 and the tip (not shown in FIG. 36 ) ofthe catheter 2040 is inserted through the central bore of the mountedassembly 2560. Visible in FIG. 36 is the inner sheath 2565, innercontrol wire 2569 and right atrium ball 2567. As seen in the figure, theright atrium ball 2567 should be aligned with the right atrium flange102. The thumbwheel 2606 is then adjusted so that the main doors 2660are above the side doors 2631, such that the main doors 2660 can close.As the closed main doors are raised using thumbwheel 2606, the rightatrium disc 2521 will rise, and the right atrium flange 102 will beginto lengthen axially and compress radially. It may be advantageous toinsure that no legs or struts of the flange are intermingled or caughtin the disc or the doors as the doors rise. Thumbwheel 2606 is used toraise the main doors while the catheter is held in a position thatallows the right atrium flange to close around the right atrium ball2567. When this operation has been correctly accomplished, the legs orstruts of the flange are evenly and tightly spaced around the rightatrium ball or flange.

The prosthesis is now brought into the catheter. In one embodiment, thefollowing procedure is used. The RA ball acts as a compression device,compressing the right atrium flange. After the right atrium flange isfirmly compressed around the right atrium ball, the outer sheath 2563 isheld firmly while the inner sheath 2565 and control wire 2569 are pulledback. This pushes outer sheath 2563 over the right atrium flange andball 2567. The ball 2567 should be pulled into the outer sheath 2563 sothat it, and the right atrium flange, are no longer visible. The travelassembly 2650 is now lowered, using the thumbwheel, until it justtouches the side doors 2631 (not shown in this view). Both sets of doorsare opened and the catheter 2040 and left and right atrium discs 2631,2621 are removed from the loading tool 2600. The left and right atriumdiscs are then removed from the catheter by pulling them apart.

The left atrium flange is now lengthened axially and compressedradially. In one embodiment, the clear loading tube 2561 has a largerdiameter than the outer sheath 2563. The clear loading tube 2561 is slidover the left atrium flange 103, pushing the left atrium flange legstogether. The clear loading tube should be slid forward or distallyuntil it completely covers the prosthesis. The control wire 2569 is thenpulled proximally, pulling the inner sheath 2565 and pulling theprosthesis into outer sheath 2563. The clear loading tube 2561 is thenremoved. The above mounting and loading procedures are accomplished in asterile environment. Alternatively, the devices and components may besterilized or re-sterilized after assembly.

Any other desired components, such as an outer shipping sheath, may thenbe added. In one embodiment, an outer shipping sheath is added in asterile manner, as shown in FIG. 37 , over the outer sheath 2563.Sterile outer shipping sheath 2571 with connector 2573 and visible cap2575 is added over the outer sheath 2563 in such a way that inner sheath2565, right atrium ball 2567 and right atrium flange 102, the centralportion of prosthesis 100, left atrium flange 103, inner control wire2569 and tip 2570 are visible from the outside of sheath 2571. In theembodiment shown, the prosthesis, including the right atrium flange 102and right atrium ball 2567, has been advanced using the control wire2569, or the outer sheath 2563 has been retracted, to allow visibilityfrom the outside of the device. The catheter 2040, with the prosthesisloaded and ready for inspection and deployment, is now ready forshipment to a hospital or other care-giving institution.

Implanting and Deploying the Prosthesis

With this embodiment, and in this configuration, a physician canimmediately inspect the prosthesis and determine whether the prosthesisis suitable for implantation into a patient. For example, the physiciancan immediately inspect, without even opening the outer package, whetherthe legs or struts of the right atrium flange are intertangled. Thephysician can also determine whether the left atrium flange or centerportion are also suitable for implantation into the patient.

As noted, the shipping sheath is advanced over the outer sheath 2653 ofthe delivery of deployment catheter 2040. Accordingly, the prosthesis100 remains within the outer sheath at all times during shipping andduring removal of the shipping sheath. In some embodiments, the outercatheter is connected at its proximal end to an irrigation system,described below, suitable for irrigating the outer sheath, and thus theprosthesis, with sterile fluid, a radiopaque dye, or other desiredsolution. A physician can thus remove the shipping sheath, flush theprosthesis with sterile solution using the irrigation system, and movethe prosthesis back and forth within the outer sheath. This allows thephysician to remove any possible bubbles from the device and thecatheter, at the same time allowing the physician to test the level ofeffort required to advance and retract the prosthesis or the outersheath with respect to each other.

Control Systems for Deploying the Prosthesis

A control system, including a control device or handle, and anirrigation system, may also be usefully employed with the catheterdescribed above. One example of a control system or handle was givenabove in FIG. 12 , and also explained. Another example is depicted inFIGS. 38A and 38B, control system 2700, including control handle 2701and irrigation system 2720. The control handle 2701 includes a housingor grip 2713 and a control trigger 2715 for a user to retract the outersheath or advance the inner control wire. The tension or pull requiredfor the trigger 2715 is set with trigger spring 2731. Thus, spring 2731controls the force needed by the user to deploy the prosthesis, i.e.,the force required to release the implant onto the septal wall.

The inner control wire is grounded to the control handle through firstplate 2711 via the flange 2041 of the inner control wire and may also besecured with adjustment screw 2715. The position of the first platewithin the handle is set by a pin and bore, or set screw or otherarrangement (not shown). The second plate 2717 is connected to the outersheath and the irrigation system, which are secured to the second platevia connector 2722. The second plate is connected via a slot (not shown)on its rear face to a pin (see FIG. 38B) on the actuation mechanismwithin the handle. The first and second plates 2711, 2717 have slots ormortises on their rear faces for riding on a tenon or shelf 2716 on theside of the front grip cover 2714.

FIG. 38B depicts the internals of the trigger mechanism. Grip 2713 alsoincludes a front cover 2714. The front cover 2714 is assembled to thegrip 2713 through fasteners 2′724 and orifices 2726 in the grip 2713 andmating parts 2721 in the cover 2714. The mating parts may be molded-innuts, threaded surfaces, or other appropriate joining components.

The internals of the trigger mechanism are largely contained within thegrip 2713. These include a trigger spring 2731, grounded between thetrigger 2715 and a pocket in grip 1713. As noted, spring 2731 determinesthe pull required to activate the trigger. This spring also provides areturn for the trigger to its resting or neutral position after eachpull by the user. Mounted within a channel 2734 in grip 2713 are avertical braking/release bar 2735, vertical driving bar 2737 and adriven horizontal bar 2738. Trigger 2715 also has an internalrectangular bore (not shown) for accommodating driven horizontal bar2738.

Driven bar 2738 in one embodiment has a rectangular cross section, whilethe driving and braking/release bars 2735, 2737 have bores withrectangular cross sections and are mounted around the driven bar via therectangular bores. Bar 2738 has a square cross section in oneembodiment, as do the matching bores in the braking and driving bars.Other configurations may also be used for the bars 2735, 2737 and 2738,and the corresponding bores. Driven bar 2738 includes a pin 2739, whichis connected directly to a bore (not shown) on the rear of the secondplate 2717. Biasing spring 2733 is grounded between the driving bar 2737and braking/release bar 2735, which is somewhat longer than driving bar2737. Biasing spring 2733 maintains compression and separation betweenthe braking and advancing bars. Trigger 2715 is also mounted around thedriven bar 2738 via a rectangular bore in this embodiment. Otherembodiments may include different geometries for driven bar 2738 and thecorresponding bores in the trigger, the driving bar and therelease/braking bar. These shapes may include rounded rectangular, ovateand others.

Compression spring 2712 biases the braking/release bar 2735 to a brakingposition by maintaining contact between the braking/release bar 2735 anddriven bar 2738. Release pin 2736 protrudes above the top of the grip2713 and is used by the operator to release the driven bar from thebraking and driving bars. When a user wishes to return the second plate2717 to a forward position, or to select a position for the secondplate, the user simply presses on pin 2736. Pressing on pin 2736 has theeffect of pushing the release/braking bar 2735 to the rear by overcomingthe compression of spring 2712. Releasing the braking bar 2735 enableseasy manual movement of the driven bar 2738 and thus second plate 2717and the outer sheath of the catheter.

The trigger mechanism works in this manner, although many otherembodiments are also possible, as also discussed in U.S. Pat. No.7,699,297. When the user activates the control mechanism by pulling thetrigger, the driven bar 2738 moves to the rear, to the right in FIGS.38A and 38B, as does the connected second plate 2717. The outer sheathis also connected to the second plate, and as the second plate moves tothe right or rear, the outer sheath does also, thus pulling the outersheath in a proximal direction and exposing more of the prosthesis andthe inner control wire. The distance traveled by the activating bar isdetermined by outer dimensions of the driven bar, the height of the borein driving bar 2737, the distance between the driving bar 2737 and thebraking/release bar 2535, and length of the vertical distance in thebore of trigger 2715. These lengths or distances determine the anglesbetween the various components and thus limit the distance that istraveled by the trigger, the driving bar and the driven bar, on eachpull of the trigger. Thus, each pull of the trigger moves the driven bar2738, the second plate 2717 and the outer sheath of the catheter 2653 apredetermined distance. This makes it straight-forward for the medicalprofessional to deploy the prosthesis. Each pull of the trigger willretract the outer sheath or advance the control wire a known andrepeatable distance.

Returning to FIG. 38A, the outer sheath 2653 is grounded to the secondplate 2717 via connector 2722, which provides both a mechanicalconnection to the control device through second plate 2717 and also afluid connection to irrigation system 2720. The connector 2722 connectsto the irrigation system 2720 through tubing 2723 to a three-way valve2725. The valve may also include other tubing connections 2723 or to oneor more connectors (not shown), and one or more optional caps 2727. Asnoted above, the irrigation system may be used by the physician to flushthe prosthesis and outer sheath with sterile fluid before use, and tocheck for and remove and bubbles in the catheter and in the prosthesis.Such fluid will exit at the far end of the outer sheath 2653 afterconnector 2573 and cap 2575 are removed.

In one embodiment, the control system 2700 includes an internalmechanism that determines the amount of movement of the first or secondplate when the trigger is pulled, and thus when the outer sheath isretracted or in the control wire and prosthesis is advanced. As noted,the amount of force needed for a single trigger actuation may be set byspring 2731. The remaining internal mechanisms, as discussed above, setsthe distance traveled. The catheter is advanced to a point where thecatheter and the prosthesis are in the desired location within thepatient, as determined by the radiopaque methods described above, or byother desirable, reliable method.

The tip of the catheter is advanced through a surgically-created openingin the atrial septum. The tip is thus in the left atrium at the start ofthe deployment process. When the trigger is pulled, the outer sheath isretracted a distance sufficient to remove the outer sheath from aroundthe left atrium legs and flange. In embodiments, this distance is about7 mm. At this point, the left atrium legs are deployed inside of theleft atrium, similar to FIG. 27 , step 6000, which shows the left flangelegs deployed from the outer sheath of catheter 111 into the leftatrium. The entire catheter system is then pulled back such that theleft atrium legs contact the septal wall, as seen in FIG. 27 , step6010. At this point, the central portion of the interatrial vent and theright atrium legs and flange are still retained by the outer sheath. Thecentral portion, still retained, is located in the septal opening. Theright atrium legs, still retained, are located in the right atrium. Asecond pull of the trigger retracts the outer sheath a distance, about 7mm, to remove the outer sheath from around the central portion and theright atrium legs, thus deploying the central portion and also deployingthe right atrium legs in the right atrium.

While 7 mm is a central value, the actual value may vary from about 3 mmto about 11 mm. In other embodiments, other travel ranges may be used.It will also be understood that this distance may vary, due to tolerancestack ups of the several components, including those of the catheter andthe control device.

At this point, the prosthesis has been deployed, and the physician willnormally inspect the deployment by one or more of the non-invasivetechniques described above to insure correct placement. If deployment issatisfactory, the physician may remove the catheter and all components,including the tip, the outer sheath, the control wire, and so forth, andfinally the guide wire used.

During implantation, the physician may use the catheter fluid system todetermine the precise placement of the end of the outer sheath and thusthe prosthesis. After the device has been advanced through the patientto a point near to the desired implantation point, the radiopaquemarkers on the left or right atrium flanges or the catheter may be used,along with fluoroscopy, echosound or other non-invasive means, todetermine the location of the device within the patient. In addition to,or instead of the radiopaque markers, the irrigation system may use aradiopaque solution, such as a barium solution or other radiopaquesolution.

The control device or handle of FIGS. 38A and 38B is merely one exampleof a delivery or deployment device and control device, as discussedherein, for use with a delivery catheter. Other control devices may alsobe used, such as additional examples depicted in FIGS. 39A, 39B and 40 .

Another embodiment of a control device is depicted in FIGS. 39A and 39B.In this embodiment, as seen in FIG. 39A, control device 2790 connects todelivery catheter 2788 for delivering a prosthesis. Control device 2790includes a control body 2791 and a control handle 2792. The control body2791 is attached or connected to the outer sheath 2784 via connector2797. The moveable control handle 2792 is attached or connected to aninner control wire 2786 (not visible in FIG. 39A) via connector 2799,and as seen in FIG. 39B, connected to the deployable prosthesis 2780.Connector 2798 is a fluid connector for supplying fluid to the inside ofcatheter 2788 and the inside of outer sheath 2784. The fluid may besterile fluid, or may be a sterile radiopaque fluid. Control handle 2792is equipped with a thumb ring 2794, while the control body 2791 includestwo finger rings 2796. Handle 2792 is also equipped with a protrudingbump or tab 2793, which is sized and designed for sequential positioningin orifices 2795.

In the sequence depicted in FIGS. 39B-E, control body 2791 remainsstationary, as does outer sheath 2784, while the control handle 2792moves progressively to the left, i.e., in a distal direction, in aseries of discrete steps, as shown. As the tab 2793 moves to the left,from the first of the orifices 2795, on the right to the last orifice onthe left, the tab is visible in one orifice after another, as shown. Atthe same time, distal tip 2785 also moves progressively to the left,distally, to sequentially deploy more and more of prosthesis 2780. Inthe middle two views of FIGS. 39C and 39D, left atrium flange 2787 isfirst partially deployed and then fully deployed. In the final view,both left and right atrium flanges 2787, 2789 are deployed. The finalview in FIG. 39E also allows a close-up of the delivery catheterdetails, including tip 2785 and non-invasive imaging markers 118 on thetip 2785, just proximal to the tip, and just distal of the deployedprosthesis 2780.

In this handle, the control handle 2792 advances control wire 2786 andthus the prosthesis 2780 in a sequenced manner that is controlled by thespacing a, b, c, between the orifices 2795 of the control body 2791. Inone embodiment, the distances are 16 mm, 5 mm and 11 mm, respectively.Other embodiments may use other discrete distances. These distances helpthe medical professional who deploys the prosthesis to more accuratelyposition the prosthesis within the patient. The device and sequenceshown in FIGS. 39A-39E uses a stationary outer sheath and a moving innercontrol wire and prosthesis. It is understood that the handle 2792 couldalternately be attached to the outer sheath, so that the tab 2793 beginsin the most distal position, as shown in the last movement of thesequence, and then the handle and tab move proximally to retract theouter sheath, thus deploying the prosthesis.

In addition, of course, non-invasive imaging is used to position thecatheter outer sheath 2784 and distal tip 2785 to a desired positionwithin the patient, i.e., with the distal top 2785 through an opening inthe atrial septum of the patient. Differences between patients may alsobe studied, and the position of the control handle 2792 may be adjustedslightly for optimal prosthesis placement. As noted in otherembodiments, markers for x-ray or echogenic imaging may be placed on theprosthesis, on the delivery device, or both, to assist in accurateplacement. Using these markers, the medical professional or surgeonimplanting the device may make adjustments to the position of the outersheath, the prosthesis and the relative distances between them. Theprosthesis may then be deployed as desired and the implanting catheter,with its tip, inner control wire, and so forth, retracted from thepatient.

In FIG. 40 , another control device 2170 includes a hollow cylindricalbody 2171, with a central channel 2172. There is a series of bores 2173for use with a set pin 2174 to set the position of a front slider 2190with a hollowed-out portion 2191 for retaining an outer sheath or outerportion of the deployment device. The outer sheath is anchored withinslider 2190 and its motion is controlled by a hand actuator 2195 with athumb grip 2197 for use in moving the slider backward or forwards. Theslider 2190 is connected to the hand actuator 2195 via an adapter 2175and pin 2178. Thus, the slider, and the position of the outer sheath maybe retained in place using a bore 2192 in the slider and retaining pin2174, along with the hand actuator 2195.

Adapter 2175 and pin 2178 connect slider 2190, and an attached outersheath, to the hand actuator 2195. Pin 2198, also known as a member, onthe bottom surface of hand actuator 2195, restrains the movement of thehand actuator to the paths molded into the outer surface of the controldevice body 2171. These paths include forward track 2184, intermediatetrack 2182, and rear track 2179. The lengths of the forward and reartracks are thus fixed or predetermined distances. The forward and reartracks 2184, 1289 are generally parallel and are separated byintermediate, transverse track 2182.

The control wire of the catheter is connected to a rear retainer 2180with one or more hollowed-out portions 2183 for securing the controlwire or inner portion of the deployment device. The rear retainer 2180is easily held in place securely and movably by a molded-in retainingnut 2181 and a threaded rod 2177. The hand wheel 2176 itself fits snuglyinto the proximal, enlarged portion of the cylindrical body 2171. Thehandwheel may be pinned in position and may rotate in place to allowtranslation of the rear retainer 2180 and thus the inner control wire.The handwheel 2176 and the threaded rod 2177 allow fine adjustments tothe position of the control wire with respect to the position of theouter sheath.

In use, the physician or other medical professional will advance thecatheter using the non-invasive imaging techniques already described.The prosthesis is advanced to the point where the catheter tip is in theleft atrium, while all portions of the prosthesis remain within theouter sheath. The slider 2190 is fixed in a distal position using pin2174, the forward or most distal orifice of the series of orifices 2173,and orifice 2192 of the slider 2190. At this point, the hand actuator isat its most distal position, and pin 2198 is all the way forward, to theright in right track 2184, i.e., the most distal position.

At this point, the left flange is positioned within the patient's leftatrium, still remaining with the outer sheath, and the retainer 2180 islocked in position and not moved further. The outer sheath is thenretracted using the slider 2190 and hand actuator 2195, similar to step6000 in FIG. 27 . In one embodiment, the outer sheath is retracted bysliding the hand actuator 2195 straight to the rear and proximally, orto the left in FIG. 40 . This movement is allowed by the rearwardmovement of member or pin 2198 in right track 2184. This movement is afixed distance, until the pin strikes the rear of the long portion 2184and the start of transverse portion 2182 of the molded-in paths and cango no further. The length of the long portion 2184 is fixed when thelong portion is molded or machined into hollow cylindrical body 2171.The distance is that needed to deploy the left flange of the interatrialpressure vent or prosthesis. The distance may also be that needed todeploy the left flange and the central or valve portion. In oneembodiment, this distance is about 7 mm. In other embodiments, thedistance may be 5 mm, 6 mm, 8 mm, 9 mm or other desired distance.

After the desired portion has been deployed, the physician may usefluoroscopy or echosound to determine the exact position of theprosthesis with the patient before proceeding. If an adjustment isneeded, the prosthesis can readily be retracted into the outer sheathfor removal or redeployment at this stage, as will be seen in some ofthe improved designs for retrieval and redeployment described below.

If continuation is indicated, the surgeon or medical professional willthen prepare to deploy the remainder of the interatrial pressure vent orprosthesis. The first step is to rotate the hand actuator 2195 a fewdegrees to the right so that pin 2198 is now in the other long track2179. The transverse portion 2182 is only about twice as wide as pin2198. Rotation of the hand actuator thus does not cause the prosthesiswithin the patient's heart to translate proximally or distally. Thesurgeon then moves the hand actuator in a proximal direction, to theleft in FIG. 40 , further retracting the outer sheath and deploying theright atrium flange into the right atrium of the patient's heart. Thelength of track 2179 is also a fixed distance, the distance fixed whenthe track is molded into the hollow cylindrical body 2171. In oneembodiment, the distance is 8 mm, a little longer than the length oftrack 2184. In other embodiments, the distance may vary, as noted above.The distances, or the length of the tracks, may be tailored to fit thepatient's anatomy, for example, by determining ahead of time the widthof the patient's septum or the dimensions of the patient's heart.

In another embodiment, not shown, the two tracks of predetermined lengthmay be a single length with a pin or other obstacle inserted at adesired point along the length of the track. The pin will preventfurther movement of pin 2198 in a proximal direction and will stop themovement of the hand actuator 2195 after it has moved a fixed orpredetermined distance, e.g., 7 mm. After the pin is removed, thesurgeon or other medical professional may continue to move the handactuator in a proximal direction along the remainder of thepredetermined or fixed length of the track.

Retrieval of the Prosthesis

In some rare situations, the deployment may not be satisfactory for anyof a number of reasons, and the prosthesis may be removed from thepatient. This very unusual situation may become apparent before theprocedure has been completed. In some cases, the need for removal maybecome apparent while the guidewire with which the procedure was begunis still in place, such, for example, the embodiments described inconnection with FIG. 19A. In other cases, it may be necessary tointroduce a guidewire to begin a removal procedure, while in other casesa guidewire is not used. If the prosthesis has not been fully deployed,removal is typically accomplished by retracting the control wireattached to the prosthesis, or by advancing the outer sheath over theprosthesis. Removal is then accomplished by merely withdrawing the outersheath and all its components. Once the prosthesis has been deployed,different techniques may be needed, as depicted herein.

Retrieval of the fully deployed prosthesis is depicted in FIGS. 41 and42 , while the tools used for retrieval are depicted in FIGS. 41, 42 and43 . The retrieval device 2750 is advanced to the desired locationwithin the patient along a guidewire 2751. Components of the retrievaldevice 2750 include an outer sheath 2752, an inner sheath 2753 and agrasper 2755, such as the three-prong grasper depicted in FIG. 41 . Inone embodiment, the outer sheath has an outer diameter of about 21 Fr(about 7 mm) while the inner diameter is about 6.7 mm. In the figure,the grasper 2755 has caught the prosthesis 2757 with one of the threeprongs 2755 a and its protruding hook or tab 2755 b. As noted, the tab2755 b may be useful for insertion into an orifice of a prosthesis legor strut, as seen in FIG. 2A, for retrieval of the prosthesis. In FIG.2A, legs 103 x of the flanges meet at a juncture, an apex or an end oftwo of the legs. Each flange of the prosthesis includes two or morelegs, usually in pairs, each pair also forming an apex where the legsmeet.

It will be recognized that one or more components of the retrievaldevice may include radiopaque components or markers for bettervisibility by non-invasive techniques, such as fluoroscopy, echo-sound,and so forth. In one embodiment, one or more of the prongs of thegrasper may be made of a radiopaque metal or material, such as themetals themselves or alloys of gold, platinum, palladium, tungsten andtantalum. In another embodiment, the prongs of may include one or moremarkers, e.g., a small dot or implant of a radiopaque material orechogenic material that will be easily detected by x-ray, fluoroscopy,echosound or other suitable non-invasive imaging technique.

In use, the retrieval device is advanced to the desired location withinthe patient, using non-invasive techniques and radiomarkers, echogenicmarkers, or other indicators on the device. The user has three controlsto manipulate the device, in addition to advancing and retracting theentire device 2750, e.g., while the internal portions are containedwithin the outer sheath 2752. The inner sheath 2753 has a control wire(not shown) as does the grasper 2755 (control wire not shown). Theretrieval basket 2758, depicted in FIGS. 42 and 43 , also is advancedand retracted using its control wire (not shown), as will be understoodby those with skill in minimally-invasive surgery arts. The grasper2755, as the innermost component and nearest the guide wire, may have amicro-rail, i.e., a lumen or longitudinal cavity, to follow preciselythe path of the guide wire. In other embodiments, it is possible toassemble the retriever so that an inner sheath is not used. For example,if the basket is assembled proximally from the grasper, and the graspersufficiently distal from the basket, an inner sheath and its controlwire may not be needed.

The user advances the device 2750 and outer sheath 2752 near the desiredpoint and verifies the location. The user may then advance the innersheath 2753 out from the outer sheath 2752. The user may then advancethe grasper 2755 from the inner sheath and maneuver the grasper and theinner sheath, or the grasper or the sheath separately as desired, tograsp the prosthesis 2757 with the prongs of the grasper. There is noseparate closing control for the grasper. The user simply maneuvers thegrasper in such a manner that when the grasper is retracted, the prongsapproach each other in a manner to grasp and retrieve the prosthesis.The control wire or control handle for the grasper in one embodiment hasa locking feature that allows the surgeon to close the grasper and notbe concerned about further manipulation of the grasper, except forwithdrawal. In one embodiment, the grasper is a three-pronged Hobbsforceps, available from Hobbs Medical, Stamford Springs, Conn., USA. Inanother embodiment, the grasper or the retrieval device may also have afluid channel for irrigating the retrieval site, much as the deploymentcatheter has a fluid channel.

Other graspers or retrievers may be used instead, such as those withfour prongs, or even other retrieval devices, such as a single prong ortab. The single tab or prong may be in the form of a short cylinder,suitable for insertion in an orifice of the struts or legs of a flangedatrial septum implantable device, as shown in FIGS. 2A and 7B. The usermaneuvers the grasper or tool so that the implantable device is hookedby one or more of the orifices, and then uses this connection toretrieve the implantable device.

In other embodiments, the implanted device may have one or more legs ofthe right atrium flange longer than most legs of the flange, making iteasier to grasp one or more of the legs or struts, as shown above inFIGS. 7B and 7C. In these embodiments, the grasper may more easilyapproach the implanted device and grasp it, whether a multi-pronggrasper is used, or whether a single tab or prong is used to grasp thelonger leg. In other embodiments, the implanted device may have a flangemore suited for retrieval, such as the conical flanges depicted in FIGS.22 and 23 . In these embodiments, it is relatively easy for a user tograsp the conical apex 450 for retrieving the implant via a grasper, asdiscussed above. Retrieval is more user-friendly also, since the shapeof the implant lends itself to being pulled in the proximal direction,i.e., towards the outside of the body of the patient.

The inner sheath and the grasper are then retracted, as shown in FIG. 42, and the basket 2758 is deployed by advancing its control wire (notshown). Basket 2758 may be made from metal mesh, such as Nitinol orother medically-acceptable, shape-memory material. Nitinol is a goodchoice because it can be trained to assume the desired basket form as itdeploys from the outer sheath. There may also be a barrier layer 2759 tohelp prevent any undesired piercings by wires or components of theprosthesis. The barrier layer may be made of a suitablemedically-acceptable cloth, such as polyester (Dacron®, for example), orother material. Once the prosthesis is grasped and the basket deployed,the grasper 2755 and the prosthesis may be retracted into the basket byadvancing the basket or retracting the grasper and prosthesis, or both.The basket, grasper and prosthesis are all withdrawn into the outersheath, which may then be safely removed from the patient with theretrieved prosthesis.

As noted, basket 2858 may be made from metal mesh, such as a mesh madefrom Nitinol or other wires. In one embodiment, Nitinol wires may be0.003 inches in diameter (about 0.08 mm in diameter); in anotherembodiment, the wires may be 0.020 inches in diameter (about 0.51 mm indiameter). Other embodiments may use flat wires or ovate-shaped wires.Basket 2759 is made from a single layer of Nitinol mesh. Otherembodiments, such as the one depicted in FIG. 43 , may use a basket 2760having two layers, i.e., a basket including an inner layer 2761 foldedover to form a second, outer layer 2762. The two-layer basket may bebetter at preventing objects within the basket from protruding outsidethe basket.

Retrieval Devices with Dilators

It is clear that the outer sheath of a retrieval device, and allcomponents, should be as small and as thin as possible for patientcomfort. Accordingly, in one embodiment, the outer sheath has an outerdiameter of about 18-20 Fr. In one embodiment, the deployed basket has alargest outer diameter of about 20 mm, which is quite large compared toa 20 Fr outer catheter outer diameter. In other embodiments, the sizesmay be larger or smaller, as needed. It is clear from inspection of thebasket in FIGS. 42 and 43 that the space used to accommodate devices forretrieving the prosthesis will be somewhat greater than the spacetypically used to deploy the prosthesis.

In order to ease the transition, a retrieval device may use a dilator onits distal end. While the tip is nominally termed a dilator, it does notexpand, rather its purpose is to maintain the dimension of its widestportion while the forceps or other device within the sheath is deployedbehind the tip. Two embodiments are depicted in FIGS. 44 and 45 . InFIG. 44 , retrieval device 2765 includes an outer sheath 2766 and devicetip 2767. The device is introduced into the patient via a guidewire2771. Retrieval device 2765 includes a grasper or forceps 2768, a jacketor outer covering 2769, as discussed above, and a braided capture sleeve2770, such as a capture sleeve made from Nitinol mesh. Retrieval device2765 also includes X-ray or echogenic markers 2774 in useful locations,such as at the distal end of the outer sheath 2766 or the dilator 2767.

In use, the device tip is deployed when the user pushes the forceps 2768distally, or withdraws the outer sheath 2766 in a proximal direction.The device tip is constrained to move axially along the guidewire 2771,and its location will thus remain in the control of the medicalprofessional deploying or retrieving the prosthesis.

The embodiment of FIG. 44 features a device tip with a rather longtransition section. When the user has advanced the retrieval device tothe desired location within the patient, the sheath is withdrawn in aproximal direction, or the forceps is advanced in a distal direction todeploy the forceps and the basket. Because the device tip has a verygradual transition, the movement and the disruption to the patient areminimal. In this embodiment, the angle A of the device tip may rangefrom about 10 degrees to about 30 degrees. Other angles may be used. Thelength of the transition section may vary from about 15 mm to about 25mm. Other lengths may be used.

Another embodiment is depicted in FIG. 45 . In this embodiment, theretrieval device 2775 also has an outer sheath 2776 and a separabledevice tip 2777. As shown in this view, the angle of the device tip ismuch greater than the previous embodiment, while the length of thedevice tip is much shorter. Retrieval device 2775 includes an innersheath 2781 and a balloon 2782 and an inflation/deflation lumen 2783.Retrieval device 2775 also includes X-ray or echogenic markers 2779 inuseful locations, such as at the distal end of the outer sheath 2776 orthe dilator 2777. The length of the transition section may vary fromabout 5 mm to about 120 mm. Other lengths may be used.

In this embodiment, the retrieval device is used with the device tip andthe internal balloon that is inflated to create a space for theretrieval device. In this embodiment, the retrieval device 2775 does notinclude a retrieval forceps at the outset. After the device tip isdeployed and the balloon is expanded to create a space, the balloon isdeflated and retracted and a retrieval forceps and basket are exchangedalong the guidewire for the balloon and the inflation equipment. Theballoon may be expanded by inflating the balloon to a pressure from 6atm to 20 atm.

Designs for Retrievability and Redeployability

FIGS. 46-49 depict additional embodiments of interatrial implantableprostheses which have been designed for easier retrieval and also forredeployment once they have been retrieved. A first improved embodiment100 a is depicted in FIGS. 46A-46B. The drawings depict several views ofbody element 100 a, showing how the ends of flange segments 102 a-102 h,103 a-103 h are rounded at their distal ends 115 and 116 to reducestress concentrations against the interatrial septum after placement.These distal ends, or apices where the strut legs intersect, includebores 109 a, 109 b, 110 a, 100 b into which radiopaque or echogenicmarkers 118 a, 118 b and 119 a, 119 b can be positioned. Using thesemarkers, the device may more easily be visualized using radiographicimaging equipment such as with x-ray, fluoroscopy, magnetic resonance,ultrasound or other imaging techniques. Markers as disclosed herein maybe applied to the ends of any segments, not just those with holes oreyelets therein. Radiopaque or echogenic markers 118 a, 118 b, 119 a,119 b can be swaged, riveted, adhered, or otherwise placed and securedinto the bores and dimensioned to be flush with the contours of thesegments. As noted previously, suture rings 117 a, 117 b may be used tosecure the left atrium flange segments 103 a-h to the right atriumflange segments 102 a-h.

The retrieval legs described herein may be made from nitinol wire,stainless steel wire (such as grades 304, 304L, 316 and 316L, amongothers), nylon sutures (e.g., polyamide), polypropylene sutures (e.g.,Prolene®), or any other material that is medically acceptable andresistant to stretching. Materials that assume a known shape aredesirable, as are materials that are visible under echographic or x-rayimaging conditions. The legs may thus take on a filamentary, thread,suture or wire shape, and may comprise a single thread or wire, or morethan one suture, filament or wire. Wires made from nitinol or othermetals may have a thickness from about 0.004 to 0.025 inches (about 0.11to 0.64 mm). Sutures may range from about 8-0 to 7 (U.S.P.designations), i.e., from about 18 to 40 AWG, or even a little thinnerthan 40 gauge. The diameters of such sutures will range from about 0.04mm to about 0.8 mm, and may apply to collagenous materials, syntheticabsorbable materials, and synthetic non-absorbable materials.

FIG. 46A depicts several retrieval legs 135 joined to a central nub 137.The retrieval legs may be made of nitinol wires or of sutures and mayextend from the bores 109 of right atrium flange legs 102 a-h to acentral juncture or nub 137. Portions of the sutures or wires may bemade from radiopaque materials or MR-visible materials so that the nub137 is visible using non-invasive imaging techniques. At a juncture, theretrieval legs may be joined into a short tube 175 and crimped into tube175. A single suture or wire loop 177, or more than one loop, may thenextend above the crimp for joining to the inner catheter control wire,or for grasping by a retrieval device. A typical crimp tube is visibleunder x-ray or echographic (sound) imaging. Thus, the tube may bestainless steel or radiopaque plastic. One embodiment of the tube has a0.035 inch i.d. (0.90 mm), 0.008 in (about 0.2 mm) wall thickness, andabout a 0.050 inch (1.3 mm) o.d. Other embodiments may be used.

Retrieval loop 177 may be radiopaque or echograpically visible, or mayinclude one or more threads that are radiopaque or echo-visible, such asa gold or platinum thread. The retrieval legs of this design do notinterfere with the function of the prosthesis but do extend a shortdistance proximally, as shown in FIG. 46B. Thus, a filter, such as athrombus filter, may be used as part of the prosthesis. In addition, thesepta described above may be used in the central portion of theprosthesis. These include the bivalve of FIG. 26 , or a tri-lobal valve,or other embodiments, such as those discussed above with respect toFIGS. 29A-29C.

The prosthesis of FIGS. 46A-46B was deployed from a catheter, asdescribed above, and is retrieved in a similar manner, described below.The retrieval device secures suture or wire 177 from the central tube orcrimp 175 with an appropriate end-effector, hook or grasper on its innercontrol wire. The inner wire of the retrieval device is then withdrawnproximally, drawing the sutures or wires into a catheter, collapsing theright atrium flange, and then drawing the remainder of the prosthesisinto the catheter. The device may then be withdrawn from the patient, ormay also be redeployed, perhaps in a better position.

A second design specifically for retrievability is depicted in FIGS.47A-47B. Prosthesis 141 is similar to prosthesis 100 a of FIGS. 46A-46B.FIG. 47A is a top view, depicting prosthesis 141 with retrieval wires orsutures 143 connected to the apices 102 a-h of the right atrium flange.In this embodiment, there are two central nubs or points 145, each forabout 180 degrees of the flange. The retrieval wires 143 are tiedtogether to form a nub 145 on each side of the right atrium flange. Asseen in FIG. 47B, the nubs 145 are then joined with a crimp tube 175,with a loop 147 of one or more retrieval wires or sutures joining thetwo crimp tubes 175 and sides of the prosthesis for removal. Theretrieval wires or sutures, and the nubs, may be made from the materialsdescribed above. As depicted in FIG. 47B, the wires or sutures avoid thecentral area of the prosthesis when deployed from catheter 173 and thusdo not interfere with the functioning or deployment of the valve. Thewires or sutures are available to assist in withdrawal and removal orredeployment of the prosthesis if needed. Retrieval loop 147 may beradiopaque or echographically visible, or may include one or morethreads that are radiopaque or echo-visible, such as a gold or platinumthread.

A third embodiment of a design for retrieval is depicted in FIGS. 48Aand 48B. In this embodiment, prosthesis 151 is very similar toprosthesis 141 above, including retrieval sutures or wires 153 frombores 109 of the right atrium flange apices 102 a-h, to a centralannular retrieval suture or wire 157. Each retrieval suture or wire 153is joined to the central retrieval thread 157 at a juncture 155. Thejunctures may simply be suture tie-offs; alternatively, the juncturescould be orifices in central wire 157 for joining retrieval sutures orwires 153. In some embodiments, an additional retrieval suture or wire147, suitable for non-invasive imaging, may be tied to the centralthread at least at one point for grasping by a retrieval device.

A fourth embodiment of a prosthesis 161 designed for retrieval andredeployment is depicted in FIG. 49 . Prosthesis 161 is similar toprosthesis 100 a, described above. In the fourth embodiment, there is aretrieval wire or suture 163 secured to each apex 102 a-h of the rightatrium flange and there is a retrieval wire or suture 167 secured toeach apex 103 a-h of the left atrium flange. The right atrium flangeretrieval wires or sutures are joined to a central point or nub 165 andsecured to an inner control wire 171 b of a catheter 173. Central nub165 may be a crimp tube and retrieval suture or wire, as describedabove. The left atrium flange retrieval wires or sutures are also joinedto a central nub 169 and secured to an inner control wire 171 a. Centralnub 169 may be a crimp tube and retrieval suture or wire, as describedabove. To deploy the prosthesis 161, the medical professional positionsthe prosthesis in the correct position within the patient and thenreleases the left atrium flange, disengaging the inner control wire fromnub 169, and also releases the right atrium flange, disengaging theinner control wire from nub 165.

If retrieval is desired, the grasper or retrieval device grasps orengages both nubs 165, 169, preferably separately, with inner controlwires 171 a, 171 b, or with graspers attached to them, to collapse therespective flange and withdraw the prosthesis, as described below. Inone embodiment, left atrium flange legs 103 a-h have a greater radius Rat their root and may even approach the septum wall at an obtuse angle,i.e., as shown in FIG. 49 . This larger radius will make it easier tocollapse the legs and struts of the flange. Once the prosthesis iswithdrawn, it may be redeployed to a better position within the patient.Prosthesis 161 is capable of having both its left and right atriumflanges collapsed. If separate control wires are used, one for eachflange, the flanges may be collapsed separately in time, thus requiringless force to withdraw. Stents for providing coronary sinus pressurerelief.

Per the discussion on heart failure, and consistent with the presentdisclosure, it may be beneficial for some patients to relieve pressurein the left atrium. One way to accomplish this is to providecommunication between the left atrium and the coronary sinus. Thecoronary sinus and its tributaries receive approximately eighty-fivepercent of coronary venous blood. The coronary sinus empties into theposterior of the right atrium, anterior and inferior to the fossaovalis. A tributary of the coronary sinus is called the great cardiacvein, which courses parallel to the majority of the posterior mitralvalve annulus, and is superior to the posterior mitral valve annulus.

Thus, by providing communication between the left atrium and thecoronary sinus, inappropriate pressures in the left atrium can beaverted, with the blood diverted to the most appropriate blood vesselpossible, the coronary sinus. In cases of mitral valve failure ordisease, it is possible that providing this communication could allowthe patient to put off or forgo mitral valve repair. This could provideadditional quality of life to the patient, while avoiding surgery thatis more involved and more delicate.

Embodiments of the stent described herein may be placed viaminimally-invasive surgery, such as through endoscopic or percutaneous(vascular access) routes, or by traditional surgical methods. Minimallyinvasive procedures are more easily tolerated by the patients, who mayalso recover much more quickly from the procedure. In embodiments wherethe device is implanted into the atrial wall via a minimally invasiveprocedure, a catheter may be used, as shown generally in FIG. 50 . Acatheter, such as an introducer catheter is introduced through a jugularvein or a subclavian vein, through the superior vena cava (SVC), alongthe path of arrows A, and into the coronary sinus CS of the heart H. Itis also possible to place the catheter via a femoral vein, through theinferior vena cava (IVC), along the path of arrows B, and into thecoronary sinus.

As is well known to those with skill in surgical arts, it is useful tofirst define the pathway via a guidewire, such as a 0.035 inch diameter(about 0.9 mm) guidewire or 0.038 inch dia. (about 1 mm) guidewire.Guidewires of other diameters may be used as needed or desired. Thecatheters may be maneuvered to their locations by carefully followingthe appropriate guidewire. It is also well known to those with skill insurgical arts that other pathways for the catheter may be used, such asthrough the pulmonary veins, or even through arterial pathways. Ifpatient anatomy suffices, however, the easier method is to go throughthe route of the SVC as discussed above.

FIG. 51 depicts one method of deploying the stents described herein. InFIG. 51 , a guide wire 10 is introduced through the jugular vein (notshown), through the superior vena cava and into the coronary sinus. Oncethe wire guide provides a path, an introducer sheath 12 may be routeddown the guide wire and into position in the coronary sinus. Theintroducer sheath or introducer catheter is used to provide vascularaccess. The introducer sheath may be a 16F or less hemostasis introducersheath. Alternatively, the subclavian vein may be used. In oneembodiment, introducer sheath 12 may be about 30 cm long. The guidewiremay be somewhat longer for ease of use. In some embodiments, theintroducer catheter may also function only as a dilator and an assistantfor preparing an opening in the wall of the left atrium. In theseembodiments, a separate placement catheter will be used. In otherembodiments, the introducer catheter may be used as the placementcatheter also.

Since the coronary sinus is largely contiguous with the left atrium,there are a variety of possible acceptable placements for the stent. Thesite selected for placement of the stent, may be made in an area wherethe tissue of the particular patient is less thick or less dense, asdetermined beforehand by non-invasive diagnostic means, such as a CTscan or radiographic technique, such as fluoroscopy or intravascularcoronary echo (IVUS).

In FIG. 52 , a bending catheter 16 is depicted, guide wire 10 is stillin place but is not shown for clarity. In one embodiment, bendingcatheter 16 may be about 145 cm long. A closer look at the introducercatheter 12 and the bending catheter 16 is depicted in FIG. 53 . Theintroducer catheter 12, equipped with a peripheral opening 13 and atleast one marker 14 for radiographic or echogenic location, is shownwithin the coronary sinus. As noted, the wire guide 10 is still inplace. In one embodiment, bending catheter 16 is about 145 cm long andhas a very flexible or floppy tip 18 for precisely positioning thecatheter. In one embodiment, the tip 18 is capable of a 90° bend so thatthe medical professional has very close control of its location and caneasily use the catheter in the desired location. Bending catheter 16 isalso equipped with one or more echogenic or radiographic markers 14 nearthe tip so its location may be discerned by non-invasive means, such asfluoroscopy or ultrasound techniques. Catheters with very flexible,e.g., floppy 90° distal tips, are available from Baylis Medical Company,Inc., Montreal, Canada.

As further shown in FIG. 54 , once the bending catheter 16 and veryflexible tip 18 are in the proper position, an RF wire 19 will be placedinto position through catheter 16 and used to ablate the tissue and topenetrate the wall between the left atrium and the coronary sinus, whichis relatively delicate tissue. Care should be taken, however, thattissue remains integral with the wall and that no loose tissue iscreated when the opening is made.

For example, bipolar or monopolar radio-frequency (RF) energy may beapplied to the desired area to ablate or vaporize tissues in the area toform an opening. Several techniques in this area of described in aco-pending provisional patent application assigned to the assignee ofthe present application and entitled “Interatrial Pressure ReliefShunt,” and filed on Feb. 10, 2011, U.S. Prov. Pat. Appl. 61/441,546 thecontents of which are hereby incorporated entirely by reference andrelied upon. Additional precautions may be taken in certain of thesetechniques, such as providing a grounding pad for the patient at leastwhen using monopolar electrical equipment.

Piezoelectric ultrasound techniques and piezoelectric ultrasound sensorsor sensor arrays in the desired abrading area, also discussed in theabove-mentioned patent document, may instead be used. Typically, DCequipment is used for RF techniques and equipment while AC equipment isused for ultrasound or piezoelectric equipment. The area in theimmediate vicinity where ablating is to take place may be protected byheat transfer equipment. For example, cooling coils may be delivered bysuitable catheters and placed in the area, such as in an annular ringsurrounding the electrodes or sensors that deliver the ablating energy.Cooling fluids, such as saline, may be pumped through the cooling coilsto counteract the very hot temperatures generated by the ablatingdevices. Ablative equipment is available, for example, from BaylisMedical Company, Inc., Montreal, Canada.

In one embodiment, the opening made in the atrial wall by ablation maythen be enlarged. The RF wire 19 with its flexible tip may be removedthrough sheath 16 and a balloon catheter 20, inserted, through sheath 16as shown in FIG. 55 . Balloon catheter 20 may also be equipped withmarkers 14. In this technique, balloon catheter 20 with tip 22 and witha balloon 24 is guided to the opening and the balloon is inserted intothe opening between the coronary sinus and the left atrium. Usinginflation lumen 26, the balloon is inflated and the opening enlarged tothe desired diameter. When the opening has been made, the balloon may bedeflated through deflation lumen 28 and then removed through the sheath16. Alternatively, any suitable dilator may be used, such as a Mullins™dilator with a needle or cutting edge or a conical distal tip of adilator catheter. The method employed must be very reliable and verycontrollable by the medical professional in all stages of itsdeployment. The size of the opening desired may range up to about 8 mm,although smaller openings may also be suitable.

Once the opening is made between the left atrium and the coronary sinus,a deployment catheter 30 is used, as depicted in FIG. 56 . Similardepictions are seen in FIGS. 8-11 above, in which the prosthesis is in acompact or folded state prior to deployment. The deployment catheter 30may be used with a guide wire 10 only or it may be used with a sheathcatheter 12, as seen above. In the figures that follow, a sheathcatheter is not shown, for simplicity, but it may be used for ease ofinsertion and then withdrawn before deployment of the stent. Thedeployment catheter 30 includes an outer sheath 32 and an inner controlwire 34. Outer sheath 32 may also include one or more radiographic orechogenic markers 36 so the sheath may be easily seen by non-invasivetechniques and its location adjusted as need for proper placement.

Deployment catheter 30 also includes a stent 40 folded up within thecatheter. As detailed below, stent 40 may be in generally in a shape ofa T, with a longer portion and a shorter perpendicular section. Thelonger portion is intended for implantation in the coronary sinus, withthe perpendicular portion extending into through atrium wall into theleft atrium. The stent should extend through the atrium wall, but theextension into the left atrium should be minimal, for example, only 3-4mm. This distance is believed to insure secure implantation withoutextending so far as to interfere with movement of the left atrium duringnormal heart operation.

Stent 40 is deployed using control wire 34, which extends backwardsthrough catheter 30 to a control device or handle (not shown) accessibleto a medical professional guiding the catheter. As is well known tothose with skill in the art, the catheter is deployed by holding thecontrol wire in place while gently withdrawing the outer sheath 32. Asthe sheath is withdrawn, the stent expands and deploys in place in thecoronary sinus. As is also well known, stent 40 is prepared frommedically acceptable prosthesis materials, such as Nitinol, stainlesssteel, MP35 or other materials. Nitinol or other shape-memory alloysallow manufacturers to prepare stents and train them to assume thedesired shape once they are returned to body temperature and aredeployed in the body. When freed of the restraints of the confiningcatheter, the stent will expand and assume the shape for which it wastrained.

Stent 40 is depicted in its undeployed state in FIG. 56 and in itsdeployed state in FIG. 57 . The deployed stent is in a general form of atube, with longer portions 41, 42 intended for implantation in thecoronary sinus and a shorter portion 43, intended to be perpendicular tolonger portions 41, 42 and for extension through the orifice made in thewall of the left atrium. In the deployed state, the shorter top portion43 is intended to protrude through the orifice. In the closer view ofFIG. 57 , it is seen that both portions of the stent has the appearanceof about eight struts 44 joined at apices 45, as also shown in greaterdetail above in FIG. 2A. In some embodiments, the stents are not made ofdiscrete struts but rather are laser cut or water-jet cut from a thin,solid tube of Nitinol or other desired material. Thus, the stents maybetter be described as a network of struts and intersections of struts.In one embodiment, at least the shorter portion 43, and also the longerportions 41, 42 include one or more markers 46 made of a radiopaque orechogenic material. In the closer view of FIG. 2A, note that the outerportions are smoothly rounded to avoid any trauma to the heart tissue,for example, with a radius of curvature greater than 0.03 inches (about0.8 mm).

The stent thus implanted should be capable of two important tasks. Thestent should be sized so that the longer part, portions 41, 42 remain inplace within the coronary sinus without movement. Accordingly, thediameter of these portions should be in the range of about 8-13 mm,perhaps in the range of 8-11 mm, because the posterior portion of thecoronary sinus, in the desired location, is a little smaller than theanterior portion. With the longer portion of the stent fixed in place,the shorter portion, or crown portion 43, will also remain in place.

Once placed, the crown also will not move and will be in a position tokeep the orifice open between the left atrium and the coronary sinus.Accordingly, it should not be necessary for the upper portion to exertmuch force on the opening, and it will be desirable for this portion tobe flexible and atraumatic rather than stiff. The coronary sinus is verysensitive to abrasion and the stent portions that reside in the coronarysinus need to be atraumatic while the LA legs need to conform to thecurvage or the radius of the opening into the left atrium chamber. Atthe same time the transverse or crown portion of the stent needs to bestrong enough to keep the freshly made opening between the coronarysinus and the left atrium from closing; this would defeat the purpose ofthe prosthesis. In other embodiments, described below, the upper portionmay form a flange, with longer or shorter extensions along thelongitudinal direction of the stent, as shown in FIGS. 58 and 59 .

In FIG. 58 , stent 50 includes a top portion or flange 51 with about 4protruding triangular struts 53. The radius of curvature is relativelytight, from about 5 mm to 15 mm, so that the flange is not held tightlyby the atrial wall in the vicinity of the flange. The flange in thisembodiment extends about 2-4 mm in a direction parallel to the coronarysinus. In FIG. 59 , stent 56 includes a top portion or flange 57 withabout 6 (not all are shown) protruding struts 58. The radius ofcurvature 59 here is somewhat looser, from about 10 mm to about 40 mm.In one embodiment, the flange extends only about 1-2 mm in a directionparallel to the coronary sinus.

One aspect of the stents for enabling communication between the leftatrium and the coronary sinus is that it may be desirable to have onlyone-way communication. One embodiment of the stent is designed to allowpressure relief of the left atrium by providing an outlet to thecoronary sinus without allowing retrograde flow. The coronary sinusdirects blood flow from several veins, such as the small, middle, greatand oblique cardiac veins, the left marginal vein and the left posteriorventricular vein. It is not desirable, however, to allow flow from thecoronary sinus into the left atrium. The stent may thus be restricted toone-way flow by providing the stent with a flow control element of thetype disclosed elsewhere herein.

FIGS. 60 and 61 depict two embodiments of a stent limited to one waycommunication by a restricting valve. In FIG. 60 , stent 60 includes atop portion 61 intended for deployment above the wall between the leftatrium and the coronary sinus. Stent 60 also includes a transverseportion 67 intended for deployment within the coronary sinus asdescribed above. Top portion 61 in this embodiment includes a multi-partflap valve 63 secured to the top portion 62 of tower 61 with sutures 64.While the flap valve 63 in this embodiment has two portions a bi-valve,that meet roughly along a diameter of the top portion, other embodimentsmay have three or more portions, again, meeting in the middle. It isalso possible to have a single flap, tethered perhaps along one side byabout 30-45 degrees of the circumference. This embodiment also includesone or more stops 65 to prevent the valve from opening in the otherdirection and allowing blood to flow from the coronary sinus into theleft atrium. The flow control element could also be a ball and socketvalve, a duckbill valve, a butterfly valve, or any other valve componentknown to those skilled in the art or as those disclosed in thecommonly-owned application mentioned above.

As is well known to those with skill in cardiac arts, the valve or flapmay be made of mammalian pericardium, such as bovine pericardial tissue,or from ovine or porcine pericardial tissue. Other suitable tissue mayalso be used. In one embodiment, the tissue is about 0.5 to about 1 mmthick. Other thicknesses may be used. The valve and the flaps aredesigned so that blood will flow through the one-way valve when thepressure differential reaches about 5-10 mm Hg.

FIG. 61 depicts another embodiment of a one-way valve useful in thestents disclosed herein. In this exploded view, valve 70 is formedwithin the top portion 71 of a coronary sinus pressure relieving stent.The valve includes a plate 75 with multiple perforations 76. Whileperforations 76 are shown as slots, they may be made of any suitableshape. The plate itself made may be made of any material suitable for invivo contact with blood, including inert polymers such as polycarbonateor polysulfone, or metals such as stainless steels, MP35N or Nitinol. Asshown, perforated plate 75 is adjacent the distal end of the stent topportion 71. On the opposite side of the perforated plate 75 is a valveelement 73 with flaps 74. In one embodiment, flaps 74 are slightlylarger than the gaps beneath the flaps, enabling the flaps to sealtightly if for some reason the pressure in the coronary sinus exceedsthe pressure in the left atrium, on the far side of the stent.

During normal operation, when the pressure in the left atrium exceedsthe pressure in the coronary sinus, blood will tend to flow from theleft atrium through the stem, and in particular at the outset, throughthe top portion 70. Blood will flow through the perforated plate 75 andsince the flaps 74 are free to flap downward, in the embodiment of FIG.61 , the blood will flow through valve element 73 and on into thecoronary sinus. However, the flaps 74 are not free to flow in theopposite direction, toward the left atrium, because their movement isprevented by the perforated plate 75. Other embodiments of check valvesor one-way valves may also be used.

Other embodiments of stents for relieving pressure may have otherconfigurations. For example, FIG. 62A depicts a T-tube stent in abefore-deployment configuration. Stent 80 includes a longer portion 81in a general shape of a cylinder for placement in a coronary sinus of apatient. The stent is constructed of short struts 84 and apices 86joining the struts, or as mentioned above, an interconnecting network ofstruts and joining areas. A shorter portion, tower 82 is folded withinthe longer portion 81. Upon deployment of the stent within a patient,the longer portion will expand if the stent has been trained to do sowhen the austenitic transition occurs upon warming to body temperature.The tower portion 82 may then be deployed from its retracted positionwithin the longer portion to its deployed position, as shown in FIG.62B.

The tower will assume its intended shape as it is deployed and as itwarms to body temperature. The tower includes a wider portion, i.e., aportion with a larger diameter that will reside within the left atrium.The tower also includes a narrower portion 83 having a diameter aboutthe diameter of the opening which was prepared for the stent. Towerportion 82 may be pushed into place, for example, by a balloon catheterif it fails to deploy properly by the “memory metal” effect. While theprincipal portion of the stem is constructed of struts and apices, inthis embodiment, the tower may be made from many more flexible, thinnerwires 88 for greater ease of deployment. In one embodiment, the wiresare 0.003 in (0.08 mm) diameter and are thus very flexible. The wiresform a porous closed “net” whose openings allow blood to flow from theleft atrium to the coronary sinus.

While the invention has been disclosed in connection with the preferredembodiments shown and described in detail, various modifications andimprovements thereon will become readily apparent to those skilled inthe art. Accordingly, the spirit and scope of the present invention isnot to be limited by the foregoing examples, but is to be understood inthe broadest sense allowable by law.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims is to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the disclosureand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

While embodiments have been disclosed and described in detail, it isunderstood that various modifications and improvements thereon willbecome readily apparent to those skilled in the art. Accordingly, thespirit and scope of the present disclosure is not limited by theforegoing examples, but is better understood by the claims below.

What is claimed is:
 1. A T-tube stent for use in a patient, comprising:a first cylindrical portion for placement in a coronary sinus of apatient, wherein the first cylindrical portion has a tubular profilewith a tubular surface; a second cylindrical portion for placement in anorifice made in a wall of a left atrium, wherein the second cylindricalportion also has a tubular profile and its proximal end joins the firstcylindrical portion along its tubular surface, wherein the secondcylindrical portion has a first configuration where its distal end isfolded within the tubular profile of the first cylindrical portion, anda second configuration where its distal end extends beyond the tubularsurface of the first cylindrical portion in a direction generallyperpendicular to an axis of the first cylindrical portion and into theleft atrium, and thereby enables fluid communication between the leftatrium and the coronary sinus; wherein both the first and secondcylindrical portions are made of a network of intersecting struts. 2.The T-tube stent according to claim 1, wherein the struts are made froma metal selected from the group consisting of shape memory alloys,nitinol, stainless steel and MP35.
 3. The T-tube stent according toclaim 1, wherein the T-tube stent further comprises at least twofeatures with properties selected from the group consisting ofradiographic properties and echogenic properties.
 4. The T-tube stentaccording to claim 1, further comprising a one way restrictive valveattached to the second cylindrical portion, wherein the one wayrestrictive valve is oriented to allow blood to flow only from the leftatrium into the coronary sinus.
 5. The T-tube stent according to claim4, wherein the one way restrictive valve comprises a multi-part flapmade from mammalian pericardium attached to the distal end of the secondcylindrical portion.
 6. The T-tube stent according to claim 1, furthercomprising a flange at the distal end of the second cylindrical portionfor engaging an atrial wall of the patient.
 7. The T-tube stentaccording to claim 1, further comprising a segmented flange on thesecond cylindrical portion for engaging an atrial wall of the patient.8. The T-tube stent of claim 1, wherein the second cylindrical portionis more flexible than the first cylindrical portion.
 9. A T-tube stentfor use in a patient, comprising: a first cylindrical portion forplacement in a coronary sinus of a patient; a second cylindrical portionfor placement in an orifice made in a wall of a left atrium, wherein aproximal end of the second cylindrical portion joins the firstcylindrical portion along its tubular surface, a flange joining a distalend of the second cylindrical portion for engaging an atrial wall of thepatient, wherein the T-tube stent has a delivery profile where thesecond cylindrical portion is folded within the first cylindricalportion, and a deployed profile where the second cylindrical portionextends beyond the first cylindrical portion in a directionperpendicular to an axis of the first cylindrical portion.
 10. TheT-tube stent of claim 9, wherein the first and the second cylindricalportions have a diameter of 8-13 mm.
 11. The T-tube stent of claim 9,wherein the second cylindrical portion is more flexible than the firstcylindrical portion.
 12. The T-tube stent of claim 9, wherein a one wayrestrictive valve is attached to the distal end of the secondcylindrical portion, and wherein the one way restrictive valve isoriented to allow blood to flow only from the left atrium into thecoronary sinus.
 13. The T-tube stent of claim 9, wherein the distal endof the second cylindrical portion is configured to extend 3-4 mm insidethe left atrium.
 14. The T-tube stent of claim 9, wherein the flangejoining the distal end of the second cylindrical portion is configuredto extend about 2-4 mm in a direction parallel to the coronary sinus.